ICU / SeaStar Medical Holding Corporation - Pengajuan SECLaporan Tahunan, Pernyataan Proksi

FORM 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 13, 2025 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporation)

FORM 8-K/A Item 2.02 Results of Operations and Financial Condition. Item 9.01 Financial Statements and Exhibits.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K/A CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 13, 2025 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporatio

SeaStar Medical Reports Second Quarter 2025 Financial Results and Provides Business Updates

Exhibit 99.1 SeaStar Medical Reports Second Quarter 2025 Financial Results and Provides Business Updates Business highlights include: • Adult NEUTRALIZE-AKI trial enrolls 31 new patients, now over 60% enrolled • Three new top-rated children’s hospitals adopt QUELIMMUNE therapy for ultra-rare pediatric Acute Kidney Injury (AKI) • Positive survival results reported from QUELIMMUNE SAVE Surveillance

Form of Series B Common Stock Purchase Warrant to Purchase Common Stock dated June 20, 2025

Exhibit 4.3 SERIES B COMMON STOCK PURCHASE WARRANT SEASTAR MEDICAL HOLDING CORPORATION Warrant Shares: Issue Date: June 23, 2025 THIS SERIES B COMMON STOCK PURCHASE WARRANT (the “Warrant”) certifies that, for value received, or its assigns (the “Holder”) is entitled, upon the terms and subject to the limitations on exercise and the conditions hereinafter set forth, at any time on or after June 23,

Form of Series A Common Stock Purchase Warrant to Purchase Common Stock dated June 20, 2025

Exhibit 4.2 SERIES A COMMON STOCK PURCHASE WARRANT SEASTAR MEDICAL HOLDING CORPORATION Warrant Shares: Issue Date: June 23, 2025 THIS SERIES A COMMON STOCK PURCHASE WARRANT (the “Warrant”) certifies that, for value received, or its assigns (the “Holder”) is entitled, upon the terms and subject to the limitations on exercise and the conditions hereinafter set forth, at any time on or after June 23,

Amended and Restated SeaStar Medical Holding Corporation 2022 Omnibus Incentive Plan

Exhibit 10.7 SEASTAR MEDICAL HOLDING CORPORATION 2022 OMNIBUS INCENTIVE PLAN (AS AMENDED AND RESTATED EFFECTIVE July 3, 2025) I PURPOSE OF THE PLAN The Plan is intended to promote the interests of the Company by providing eligible persons in the Company’s service with the opportunity to acquire a proprietary interest, or otherwise increase their proprietary interest, in the Company, or receive mon

Form of Pre-Funded Warrant to Purchase Common Stock dated June 20, 2025

Exhibit 4.1 PRE-FUNDED COMMON STOCK PURCHASE WARRANT SEASTAR MEDICAL HOLDING CORPORATION Warrant Shares: Initial Exercise Date: June 23, 2025 THIS PRE-FUNDED COMMON STOCK PURCHASE WARRANT (the “Warrant”) certifies that, for value received, or its assigns (the “Holder”) is entitled, upon the terms and subject to the limitations on exercise and the conditions hereinafter set forth, at any time on or

SeaStar Medical Reports Second Quarter 2025 Financial Results and Provides Business Updates

Exhibit 99.1 SeaStar Medical Reports Second Quarter 2025 Financial Results and Provides Business Updates Business highlights include: • Adult NEUTRALIZE-AKI trial enrolls 31 new patients, now over 60% enrolled • Three new top-rated children’s hospitals adopt QUELIMMUNE therapy for ultra-rare pediatric Acute Kidney Injury (AKI) • Positive survival results reported from QUELIMMUNE SAVE Surveillance

Form of Placement Agent Warrant to Purchase Common Stock dated June 20, 2025

Exhibit 4.4 PLACEMENT AGENT COMMON STOCK PURCHASE WARRANT SEASTAR MEDICAL HOLDING CORPORATION Warrant Shares: Issue Date: June 23, 2025 THIS PLACEMENT AGENT COMMON STOCK PURCHASE WARRANT (the “Warrant”) certifies that, for value received, or its assigns (the “Holder”) is entitled, upon the terms and subject to the limitations on exercise and the conditions hereinafter set forth, at any time on or

FORM 8-K Item 2.02 Results of Operations and Financial Condition. Item 9.01 Financial Statements and Exhibits.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 13, 2025 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporation)

Condensed Consolidated Balance Sheets Condensed Consolidated Statements of Operations

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2025 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM TO Commission File Number 001-39927 SEASTAR MED

Amended and Restated SeaStar Medical Holding Corporation 2022 Omnibus Incentive Plan.

EXHIBIT 99.1 SEASTAR MEDICAL HOLDING CORPORATION 2022 OMNIBUS INCENTIVE PLAN (AS AMENDED AND RESTATED EFFECTIVE JULY 3, 2025) I PURPOSE OF THE PLAN The Plan is intended to promote the interests of the Company by providing eligible persons in the Company’s service with the opportunity to acquire a proprietary interest, or otherwise increase their proprietary interest, in the Company, or receive mon

As filed with the Securities and Exchange Commission on August 8, 2025

As filed with the Securities and Exchange Commission on August 8, 2025 Registration No.

As filed with the Securities and Exchange Commission on August 8, 2025

As filed with the Securities and Exchange Commission on August 8, 2025 Registration No.

CALCULATION OF FILING FEE TABLES Form S-8 (Form Type) SeaStar Medical Holding Corporation (Exact Name of Registrant as Specified in its Charter) TABLE 1 - NEWLY REGISTERED SECURITIES

Exhibit 107 CALCULATION OF FILING FEE TABLES Form S-8 (Form Type) SeaStar Medical Holding Corporation (Exact Name of Registrant as Specified in its Charter) TABLE 1 - NEWLY REGISTERED SECURITIES Security Type Security Class Title Fee Calculation Rule Amount Registered (1) Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Equity Common Stock, par value $0.

FORM 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 08, 2025 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporation)

SeaStar Medical Holding Corporation Up to $2,160,113 of Common Stock

Filed Pursuant to Rule 424(b)(5) Registration No. 333-275968 PROSPECTUS SUPPLEMENT (To Prospectus Dated December 22, 2023) SeaStar Medical Holding Corporation Up to $2,160,113 of Common Stock We previously entered into an at the market offering agreement (the “Offering Agreement”), dated August 20, 2024, with H.C. Wainwright & Co., LLC, as sales agent (the “Sales Agent” or “Wainwright”), relating

Filing Fee Table

Ex-Filing Fees CALCULATION OF FILING FEE TABLES S-1 SeaStar Medical Holding Corp Table 1: Newly Registered and Carry Forward Securities Line Item Type Security Type Security Class Title Notes Fee Calculation Rule Amount Registered Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Newly Registered Securities Fees to be Paid Equity Common Stock, par value $0.

FORM 8-K Item 3.01 Notice of Delisting or Failure to Satisfy a Continued Listing Rule or Standard; Transfer of Listing.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 26, 2023 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporation) (

FORM 8-K/A Item 3.01 Notice of Delisting or Failure to Satisfy a Continued Listing Rule or Standard; Transfer of Listing.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K/A CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 31, 2025 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporation)

SeaStar Medical Announces $4.4 Million Registered Direct Offering Priced At-the-Market Under Nasdaq Rules

Exhibit 99.1 SeaStar Medical Announces $4.4 Million Registered Direct Offering Priced At-the-Market Under Nasdaq Rules DENVER, July 31, 2025 (GLOBE NEWSWIRE) - SeaStar Medical Holding Corporation (Nasdaq: ICU), a commercial-stage healthcare company focused on transforming treatments for critically ill patients facing organ failure and potential loss of life, today announced it has entered into a d

SeaStar Medical Holding Corporation 4,960,544 Shares of Common Stock

Filed Pursuant to Rule 424(b)(5) Registration No. 333-275968 PROSPECTUS SUPPLEMENT (To Prospectus Dated December 22, 2023) SeaStar Medical Holding Corporation 4,960,544 Shares of Common Stock Pursuant to this prospectus supplement and the accompanying prospectus, we are offering in a registered direct offering to certain purchasers 4,960,544 shares of our common stock, par value $0.0001 per share

Form of Placement Agent Warrant to Purchase Common Stock

Exhibit 4.2 NEITHER THIS SECURITY NOR THE SECURITIES FOR WHICH THIS SECURITY IS EXERCISABLE HAVE BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE IN RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD EXCEPT PURSUANT TO AN EFFECTIVE REGISTR

FORM 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 31, 2025 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporation) (

Form of Common Stock Purchase Warrant to Purchase Common Stock

Exhibit 4.1 NEITHER THIS SECURITY NOR THE SECURITIES FOR WHICH THIS SECURITY IS EXERCISABLE HAVE BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE IN RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD EXCEPT PURSUANT TO AN EFFECTIVE REGISTR

Form of Securities Purchase Agreement by and among the Company and the purchasers party thereto

Exhibit 10.1 SECURITIES PURCHASE AGREEMENT This Securities Purchase Agreement (this “Agreement”) is dated as of July 31, 2025, between SeaStar Medical Holding Corporation, a Delaware corporation (the “Company”), and each purchaser identified on the signature pages hereto (each, including its successors and assigns, a “Purchaser” and collectively the “Purchasers”). WHEREAS, subject to the terms and

FORM 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 14, 2025 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporation) (

Form of Securities Purchase Agreement by and among the Company and the Purchasers (incorporated by reference to Exhibit 10.1 of Form 8-K filed by the registrant on July 14, 2025)

Exhibit 10.1 SECURITIES PURCHASE AGREEMENT This Securities Purchase Agreement (this “Agreement”) is dated as of July 10, 2025, between SeaStar Medical Holding Corporation, a Delaware corporation (the “Company”), and each purchaser identified on the signature pages hereto (each, including its successors and assigns, a “Purchaser” and collectively the “Purchasers”). WHEREAS, subject to the terms and

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 10, 2025 SeaStar Medical Hol

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 10, 2025 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporation) (

SeaStar Medical Announces $4 Million Registered Direct Offering Priced At-the-Market Under Nasdaq Rules

Exhibit 99.1 SeaStar Medical Announces $4 Million Registered Direct Offering Priced At-the-Market Under Nasdaq Rules DENVER, July 10, 2025 - SeaStar Medical Holding Corporation (Nasdaq: ICU), a commercial-stage healthcare company focused on transforming treatments for critically ill patients facing organ failure and potential loss of life today announced it has entered into a definitive agreement

Form of Common Stock Purchase Warrant to Purchase Common Stock

Exhibit 4.2 NEITHER THIS SECURITY NOR THE SECURITIES FOR WHICH THIS SECURITY IS EXERCISABLE HAVE BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE IN RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD EXCEPT PURSUANT TO AN EFFECTIVE REGISTR

Form of Pre-Funded Warrants to Purchase Common Stock (incorporated by reference to Exhibit 4.1 of Form 8-K filed on July 14, 2025)

Exhibit 4.1 PRE-FUNDED COMMON STOCK PURCHASE WARRANT SeaStar Medical Holding Corporation Warrant Shares: Issue Date: July 11, 2025 Initial Exercise Date: July 11, 2025 THIS PRE-FUNDED COMMON STOCK PURCHASE WARRANT (the “Warrant”) certifies that, for value received, or its assigns (the “Holder”) is entitled, upon the terms and subject to the limitations on exercise and the conditions hereinafter se

Form of Placement Agent Warrant to Purchase Common Stock

Exhibit 4.3 NEITHER THIS SECURITY NOR THE SECURITIES FOR WHICH THIS SECURITY IS EXERCISABLE HAVE BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE IN RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD EXCEPT PURSUANT TO AN EFFECTIVE REGISTR

SeaStar Medical Holding Corporation 4,841,232 Shares of Common Stock 401,232 Pre-Funded Warrants to purchase up to 401,232 Shares of Common Stock

Filed Pursuant to Rule 424(b)(5) Registration No. 333-275968 PROSPECTUS SUPPLEMENT (To Prospectus Dated December 22, 2023) SeaStar Medical Holding Corporation 4,841,232 Shares of Common Stock 401,232 Pre-Funded Warrants to purchase up to 401,232 Shares of Common Stock Pursuant to this prospectus supplement and the accompanying prospectus, we are offering in a registered direct offering to certain

SeaStar Medical Holding Corporation

Filed Pursuant to Rule 424(b)(5) Registration No. 333-275968 Prospectus Supplement (To Prospectus dated December 22, 2023) SeaStar Medical Holding Corporation We previously entered into an at the market offering agreement (the “Offering Agreement”) with H.C. Wainwright & Co., LLC (“Wainwright”) pursuant to which we may offer and sell shares of our common stock from time to time through Wainwright,

FORM 8-K Item 5.07 Submission of Matters to a Vote of Security Holders.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 03, 2025 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporation) (

SeaStar Medical Announces Positive Nasdaq Listing Determination

Exhibit 99.1 SeaStar Medical Announces Positive Nasdaq Listing Determination DENVER, CO., JULY 2, 2025 – SeaStar Medical Holding Corporation (Nasdaq: ICU), a commercial-stage healthcare company focused on transforming treatments for critically ill patients facing organ failure and potential loss of life,announced today that it has received confirmation from The Nasdaq Stock Market that the Company

FORM 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 01, 2025 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporation) (

FORM 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 17, 2025 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporation) (

SeaStar Medical Announces Pricing of Up to $8 Million Public Offering $4 million upfront with up to an additional $4 million of potential aggregate gross proceeds upon the exercise in full of short-term warrants

Exhibit 99.1 SeaStar Medical Announces Pricing of Up to $8 Million Public Offering $4 million upfront with up to an additional $4 million of potential aggregate gross proceeds upon the exercise in full of short-term warrants DENVER, CO (June 20, 2025) – SeaStar Medical Holding Corporation (the “Company” or “SeaStar Medical”) (Nasdaq: ICU), a commercial-stage healthcare company focused on transform

4,935,385 Shares of Common Stock and accompanying Series A Warrants to purchase up to 4,935,385 Shares of Common Stock and accompanying Series B Warrants to purchase up to 4,935,385 Shares of Common Stock 1,218,462 Pre-Funded Warrants to purchase up

Filed Pursuant to Rule 424(b)(4) Registration No. 333-288065 PROSPECTUS 4,935,385 Shares of Common Stock and accompanying Series A Warrants to purchase up to 4,935,385 Shares of Common Stock and accompanying Series B Warrants to purchase up to 4,935,385 Shares of Common Stock 1,218,462 Pre-Funded Warrants to purchase up to 1,218,462 Shares of Common Stock and accompanying Series A Warrants to purc

Form of Pre-Funded Warrant.

Exhibit 4.11 PRE-FUNDED COMMON STOCK PURCHASE WARRANT SEASTAR MEDICAL HOLDING CORPORATION Warrant Shares: Initial Exercise Date: , 2025 THIS PRE-FUNDED COMMON STOCK PURCHASE WARRANT (the “Warrant”) certifies that, for value received, or its assigns (the “Holder”) is entitled, upon the terms and subject to the limitations on exercise and the conditions hereinafter set forth, at any time on or after

Filing Fee Table

Exhibit 107 Calculation of Filing Fee Tables S-1 (Form Type) SeaStar Medical Holding Corporation (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered and Carry Forward Securities Security Type Security Class Title Fee Calculation or Carry Forward Rule Amount Registered Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price(1)(2) Fee Rate Amount of Registration Fee Carry Forward Form Type Carry Forward File Number Carry Forward Initial effective date Filing Fee Previously Paid In Connection with Unsold Securities to be Carried Forward Newly Registered Securities Fees to be Paid Equity Common Stock, par value $0.

Form of Series B Common Stock Purchase Warrant

Exhibit 4.13 SERIES B COMMON STOCK PURCHASE WARRANT SEASTAR MEDICAL HOLDING CORPORATION Warrant Shares: Issue Date: , 2025 THIS SERIES B COMMON STOCK PURCHASE WARRANT (the “Warrant”) certifies that, for value received, or its assigns (the “Holder”) is entitled, upon the terms and subject to the limitations on exercise and the conditions hereinafter set forth, at any time on or after [the Stockhold

Form of Series A Common Stock Purchase Warrant

Exhibit 4.12 SERIES A COMMON STOCK PURCHASE WARRANT SEASTAR MEDICAL HOLDING CORPORATION Warrant Shares: Issue Date: , 2025 THIS SERIES A COMMON STOCK PURCHASE WARRANT (the “Warrant”) certifies that, for value received, or its assigns (the “Holder”) is entitled, upon the terms and subject to the limitations on exercise and the conditions hereinafter set forth, at any time on or after [the Stockhold

As filed with the Securities and Exchange Commission on June 20, 2025

As filed with the Securities and Exchange Commission on June 20, 2025 Registration No.

Form of Securities Purchase Agreement.

Exhibit 10.13 SECURITIES PURCHASE AGREEMENT This Securities Purchase Agreement (this “Agreement”) is dated as of June [*], 2025, between SeaStar Medical Holding Corporation, a Delaware corporation (the “Company”), and each purchaser identified on the signature pages hereto (each, including its successors and assigns, a “Purchaser” and collectively the “Purchasers”). WHEREAS, subject to the terms a

Amendment to the Engagement Agreement, dated April 1, 2025, by and between SeaStar Medical Holding Corporation and H.C. Wainwright & Co., LLC.

Exhibit 10.15 Execution Version April 1, 2025 STRICTLY CONFIDENTIAL SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 Attn: Eric Schlorff, Chief Executive Officer Dear Mr. Schlorff: Reference is made to that certain engagement agreement (the “Engagement Agreement”), dated as of May 17, 2024, as amended on November 13, 2024 by and between SeaStar Medical Holding Cor

Form of Placement Agent Warrant

Exhibit 4.14 PLACEMENT AGENT COMMON STOCK PURCHASE WARRANT SEASTAR MEDICAL HOLDING CORPORATION Warrant Shares: Issue Date: , 2025 THIS PLACEMENT AGENT COMMON STOCK PURCHASE WARRANT (the “Warrant”) certifies that, for value received, or its assigns (the “Holder”) is entitled, upon the terms and subject to the limitations on exercise and the conditions hereinafter set forth, at any time on or after

Engagement Agreement, dated May 17, 2024, by and between SeaStar Medical Holding Corporation and H.C. Wainwright & Co., LLC.

Exhibit 10.14 Execution Version May 17, 2024 STRICTLY CONFIDENTIAL SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, Colorado 80216 Attn: Eric Schlorff, Chief Executive Officer Dear Mr. Schlorff: This letter agreement (this “Agreement”) constitutes the agreement between SeaStar Medical Holding Corporation (the “Company”) and H.C. Wainwright & Co., LLC (“Wainwright”), that W

SEASTAR MEDICAL HOLDING CORPORATION

SEASTAR MEDICAL HOLDING CORPORATION June 17, 2025 VIA EDGAR United States Securities and Exchange Commission Division of Corporate Finance 100 F Street, N.

As filed with the Securities and Exchange Commission on June 16, 2025

As filed with the Securities and Exchange Commission on June 16, 2025 Registration No.

Filing Fee Table

Exhibit 107 Calculation of Filing Fee Tables S-1 (Form Type) SeaStar Medical Holding Corporation (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered and Carry Forward Securities Security Type Security Class Title Fee Calculation or Carry Forward Rule Amount Registered Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price(1)(2) Fee Rate Amount of Registration Fee Carry Forward Form Type Carry Forward File Number Carry Forward Initial effective date Filing Fee Previously Paid In Connection with Unsold Securities to be Carried Forward Newly Registered Securities Fees to be Paid Equity Common Stock, par value $0.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 6, 2025 SeaStar Medical Hold

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 6, 2025 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporation) (C

Form of Confidential Bonus Release Agreement (incorporated by reference to Exhibit 10.1 of Form 8-K filed by the registrant on June 11, 2025)

Exhibit 10.1 CONFIDENTIAL BONUS RELEASE AGREEMENT This Confidential Bonus Release Agreement (“Agreement”) is entered into by and between SeaStar Medical, Inc. (the “Company”) and NAME (“you” or “your”), collectively (the “Parties”). In consideration of the mutual promises contained in this Agreement, you and the Company agree as follows: 1. Effective Date. The Effective Date of this Agreement is t

Up to 4,736,406 Shares Common Stock SeaStar Medical Holding Corporation

Filed Pursuant to Rule 424(b)(3) Registration No. 333-287403 PROSPECTUS Up to 4,736,406 Shares Common Stock SeaStar Medical Holding Corporation This prospectus relates to the resale, from time to time, of up to 4,736,406 shares of our common stock, par value $0.0001 per share (“Common Stock”), by Lincoln Park Capital Fund, LLC (“Lincoln Park” or the “selling stockholder”). The shares of Common Sto

Confidential Treatment Requested By SeaStar Medical Holding Corporation Pursuant to 17 C.F.R. Section 200.83 REGISTRATION STATEMENT As filed with the Securities and Exchange Commission on May 23, 2025

Confidential Treatment Requested By SeaStar Medical Holding Corporation Pursuant to 17 C.

SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216

SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 May 22, 2025 VIA EDGAR United States Securities and Exchange Commission Division of Corporation Finance 100 F.

Filing Fee Table

Exhibit 107 Calculation of Filing Fee Tables S-1 (Form Type) SeaStar Medical Holding Corporation (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered and Carry Forward Securities Security Type Security Class Title Fee Calculation or Carry Forward Rule Amount Registered Proposed Maximum Offering Price Per Unit (1) Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Carry Forward Form Type Carry Forward File Number Carry Forward Initial effective date Filing Fee Previously Paid In Connection with Unsold Securities to be Carried Forward Newly Registered Securities Fees to be Paid Equity Common Stock, par value $0.

REGISTRATION STATEMENT As filed with the Securities and Exchange Commission on May 19, 2025

REGISTRATION STATEMENT As filed with the Securities and Exchange Commission on May 19, 2025 Registration No.

Condensed Consolidated Balance Sheets Condensed Consolidated Statements of Operations

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2025 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM TO Commission File Number 001-39927 SEASTAR ME

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 14, 2025 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporation) (C

SeaStar Medical Reports First Quarter 2025 Financial Results and Provides Business Updates

Exhibit 99.1 SeaStar Medical Reports First Quarter 2025 Financial Results and Provides Business Updates • QUELIMMUNE adoption drives four-fold increase in sequential quarter net revenue • NEUTRALIZE AKI trial exceeds 50% enrollment, triggers start of Interim Analysis • Webcast Today at 4:30 pm Eastern Time DENVER, CO (May 14, 2025) – SeaStar Medical Holding Corporation (Nasdaq: ICU) a commercial-s

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ______)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ______)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ______)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.

Purchase Agreement, dated April 25, 2025, by and between SeaStar Medical Holding Corporation and Lincoln Park Capital Fund, LLC (incorporated by reference to Exhibit 10.1 of Form 8-K filed by the registrant on April 25, 2025).

Exhibit 10.1 PURCHASE AGREEMENT THIS PURCHASE AGREEMENT (the “Agreement”), dated effective as of April 25, 2025, is made by and between SEASTAR MEDICAL HOLDING CORPORATION, a Delaware corporation (the “Company”), and LINCOLN PARK CAPITAL FUND, LLC, an Illinois limited liability company (the “Investor”). Capitalized terms used herein and not otherwise defined herein are defined in Section 1 hereof.

FORM 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 25, 2025 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporation)

SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216

SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 April 25, 2025 VIA EDGAR United States Securities and Exchange Commission Division of Corporation Finance 100 F.

Registration Rights Agreement, dated April 25, 2025, by and between SeaStar Medical Holding Corporation and Lincoln Park Capital Fund, LLC (incorporated by reference to Exhibit 10.1 of Form 8-K filed by the registrant on April 25, 2025).

Exhibit 10.2 REGISTRATION RIGHTS AGREEMENT THIS REGISTRATION RIGHTS AGREEMENT (this “Agreement”), dated as of April 25, 2025, is made by and between SEASTAR MEDICAL HOLDING CORPORATION, a Delaware corporation (the “Company”), and LINCOLN PARK CAPITAL FUND, LLC, an Illinois limited liability company (together with its permitted assigns, the “Buyer”). Capitalized terms used herein and not otherwise

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K/A (Amendment No. 1)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K/A (Amendment No. 1) (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM TO Commission File Number 001-3

Filing Fee Table.

Exhibit 107 Calculation of Filing Fee Tables S-3 (Form Type) SeaStar Medical Holding Corporation (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered and Carry Forward Securities Security Type Security Class Title Fee Calculation or Carry Forward Rule Amount Registered Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Carry Forward Form Type Carry Forward File Number Carry Forward Initial effective date Filing Fee Previously Paid In Connection with Unsold Securities to be Carried Forward Newly Registered Securities Fees to be Paid Equity Common Stock, par value $0.

As filed with the Securities and Exchange Commission on April 22, 2025

As filed with the Securities and Exchange Commission on April 22, 2025 Registration No.

As filed with the Securities and Exchange Commission on April 22, 2025

As filed with the Securities and Exchange Commission on April 22, 2025 Registration No.

CALCULATION OF FILING FEE TABLES Form S-8 (Form Type) SeaStar Medical Holding Corporation (Exact Name of Registrant as Specified in its Charter) TABLE 1 - NEWLY REGISTERED SECURITIES

Exhibit 107 CALCULATION OF FILING FEE TABLES Form S-8 (Form Type) SeaStar Medical Holding Corporation (Exact Name of Registrant as Specified in its Charter) TABLE 1 - NEWLY REGISTERED SECURITIES Security Type Security Class Title Fee Calculation Rule Amount Registered (1) Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Equity Common Stock, par value $0.

Amended and Restated SeaStar Medical Holding Corporation 2022 Omnibus Incentive Plan.

EXHIBIT 99.1 SEASTAR MEDICAL HOLDING CORPORATION 2022 OMNIBUS INCENTIVE PLAN (AS AMENDED AND RESTATED EFFECTIVE JUNE 4, 2024) I PURPOSE OF THE PLAN The Plan is intended to promote the interests of the Company by providing eligible persons in the Company’s service with the opportunity to acquire a proprietary interest, or otherwise increase their proprietary interest, in the Company, or receive mon

SeaStar Medical Holding Corporation Up to $7,433,000 of Common Stock

Filed Pursuant to Rule 424(b)(5) Registration No. 333-275968 Prospectus Supplement (To Prospectus dated December 22, 2023) SeaStar Medical Holding Corporation Up to $7,433,000 of Common Stock We previously entered into an at the market offering agreement (the “Offering Agreement”) with H.C. Wainwright & Co., LLC (“Wainwright”) pursuant to which we may offer and sell shares of our common stock from

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 28, 2025 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporation)

Exhibit 4.3

Exhibit 4.3 DESCRIPTION OF SECURITIES The following summary of the material terms of our securities is not intended to be a complete summary of the rights and preferences of such securities. The descriptions below are qualified by reference to the actual text of the Third Amended and Restated Certificate of Incorporation of SeaStar Medical Holding Corporation, as amended (the “Charter”) and our Se

SeaStar Medical Holding Corporation Insider Trading Policy

Exhibit 19.1 SEASTAR MEDICAL HOLDING CORPORATION TRADES IN SECURITIES BY DIRECTORS, OFFICERS AND COMPANY PERSONNEL AND TREATMENT OF CONFIDENTIAL INFORMATION (ALSO KNOWN AS THE “INSIDER TRADING POLICY”) (as adopted October 20, 2022) This policy (the “Policy”) was adopted by the Board of Directors (the “Board”) of SeaStar Medical Holding Corporation, a Delaware corporation (the “Company”), on Octobe

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K

7 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One)e ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM TO Commission File Number 001-39927 SEASTAR MEDI

Third Certificate of Amendment to the Third Amended and Restated Certificate of Incorporation of SeaStar Medical Holding Corporation (incorporated by reference to Exhibit 3.4 to Form 10-K filed by registrant on March 27, 2025).

Exhibit 3.4 Third Certificate of Amendment to the Third Amended and Restated Certificate of Incorporation of SeaStar Medical Holding Corporation SeaStar Medical Holding Corporation (the “Corporation”), a corporation organized and existing under the General Corporation Law of the State of Delaware (the “DGCL”), does hereby certify that: 1. The name of the Corporation is SeaStar Medical Holding Corp

SeaStar Medical Reports Fourth Quarter and Full Year 2024 Financial Results and Provides Business Updates Webcast Today at 4:30 pm Eastern Time

SeaStar Medical Reports Fourth Quarter and Full Year 2024 Financial Results and Provides Business Updates Webcast Today at 4:30 pm Eastern Time DENVER, CO.

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 27, 2025 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporation)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 20, 2025 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporation)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 11, 2025 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporation)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. 1)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. 1) Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☒ Defi

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 14A (Rule 14a-101) Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. _____)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 14A (Rule 14a-101) Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 14A (Rule 14a-101) Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. _____)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 14A (Rule 14a-101) Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.

Regulation FD Disclosure, Entry into a Material Definitive Agreement, Unregistered Sales of Equity Securities, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 31, 2025 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporation

Form of Pre-Funded Warrant to Purchase Common Stock (incorporated by reference to Exhibit 4.1 of Form 8-K dated February 3, 2025).

Exhibit 4.1 PRE-FUNDED COMMON STOCK PURCHASE WARRANT SeaStar Medical Holding Corporation Warrant Shares: 2,816,412 Issue Date: February 3, 2025 Initial Exercise Date: February 3, 2025 THIS PRE-FUNDED COMMON STOCK PURCHASE WARRANT (the “Warrant”) certifies that, for value received, or its assigns (the “Holder”) is entitled, upon the terms and subject to the limitations on exercise and the condition

SeaStar Medical Announces $6 Million Registered Direct Offering Priced At-the-Market

Exhibit 99.1 SeaStar Medical Announces $6 Million Registered Direct Offering Priced At-the-Market DENVER (January 31, 2025) – SeaStar Medical Holding Corporation (Nasdaq: ICU) (SeaStar Medical), today announced it has entered into a securities purchase agreement with a single institutional investor for the issuance and sale of an aggregate of 3,529,412 shares of its common stock (or pre-funded war

Form of Placement Agent Warrant (incorporated by reference to Exhibit 4.3 of Form 8-K filed by the registrant on February 3, 2025).

Exhibit 4.3 PLACEMENT AGENT COMMON STOCK PURCHASE WARRANT SeaStar Medical Holding Corporation Warrant Shares: Issue Date: February 3, 2025 Initial Exercise Date: February 3, 2025 THIS PLACEMENT AGENT COMMON STOCK PURCHASE WARRANT (the “Warrant”) certifies that, for value received, or its assigns (the “Holder”) is entitled, upon the terms and subject to the limitations on exercise and the condition

SeaStar Medical Holding Corporation 713,000 Shares of Common Stock Pre-Funded Warrants to Purchase 2,816,412 Shares of Common Stock 2,816,412 Shares of Common Stock Underlying the Pre-Funded Warrants Placement Agent Warrants to Purchase 247,059 Share

Filed Pursuant to Rule 424(b)(5) Registration No. 333-275968 PROSPECTUS SUPPLEMENT (To Prospectus Dated December 22, 2023) SeaStar Medical Holding Corporation 713,000 Shares of Common Stock Pre-Funded Warrants to Purchase 2,816,412 Shares of Common Stock 2,816,412 Shares of Common Stock Underlying the Pre-Funded Warrants Placement Agent Warrants to Purchase 247,059 Shares of Common Stock 247,059 S

Securities Purchase Agreement (incorporated by reference to Exhibit 10.1 of Form 8-K filed by the registrant on February 3, 2025).

Exhibit 10.1 SECURITIES PURCHASE AGREEMENT This Securities Purchase Agreement (this “Agreement”) is dated as of January 31, 2025, between SeaStar Medical Holding Corporation, a Delaware corporation (the “Company”), and each purchaser identified on the signature pages hereto (each, including its successors and assigns, a “Purchaser” and collectively the “Purchasers”). WHEREAS, subject to the terms

Form of Common Stock Purchase Warrant (incorporated by reference to Exhibit 4.2 of Form 8-K filed by the registrant on February 3, 2025).

Exhibit 4.2 NEITHER THIS SECURITY NOR THE SECURITIES FOR WHICH THIS SECURITY IS EXERCISABLE HAVE BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE IN RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD EXCEPT PURSUANT TO AN EFFECTIVE REGISTR

Notice of Delisting or Failure to Satisfy a Continued Listing Rule or Standard; Transfer of Listing

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 28, 2025 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporation

January 2025 www.SeaStarMedical.com Nasdaq: ICU Investor Presentation Bringing organ - restoring solutions to critically ill patients Forward - looking statements This presentation contains certain forward - looking statements within the meaning of t

Exhibit 99.1 January 2025 www.SeaStarMedical.com Nasdaq: ICU Investor Presentation Bringing organ - restoring solutions to critically ill patients Forward - looking statements This presentation contains certain forward - looking statements within the meaning of the “safe harbor” provisions of the Private Securities Litigation Reform Act of 1955. These forward - looking statements include, without

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 13, 2025 SeaStar Medical

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 13, 2025 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporation

Notice of Delisting or Failure to Satisfy a Continued Listing Rule or Standard; Transfer of Listing

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 24, 2024 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporatio

Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 13, 2024 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporatio

November 27, 2024

Dorsey & Whitney LLP 111 S Main St Salt Lake City, UT 84111 Tel. +1 (801) 933-7360 Fax: +1 (801) 933-7373 www.dorsey.com Josh Erekson Of Counsel +1 (801) 933-4083 [email protected] November 27, 2024 VIA EDGAR AS CORRESPONDENCE United States Securities and Exchange Commission Division of Corporation Finance Office of Industrial Applications and Services 100 F Street, N.E. Washington, D.C. 205

Submission of Matters to a Vote of Security Holders

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 26, 2024 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporatio

ICU / SeaStar Medical Holding Corporation / Ayrton Capital LLC Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No.

Financial Tables to Follow SeaStar Medical Holding Corporation Condensed Consolidated Balance Sheets (in thousands, except for share and per-share amounts)

Exhibit 99.1 SeaStar Medical Reports Third Quarter 2024 Financial Results and Provides a Business Update DENVER (November 13, 2024) – SeaStarMedical Holding Corporation (Nasdaq: ICU) (“SeaStar Medical” or the “Company”), a commercial-stage medical device company developing proprietary solutions to reduce the consequences of hyperinflammation on vital organs, reports financial results for the three

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 13, 2024 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporatio

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM TO Commission File Number 001-39927 SEASTA

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 14A (Rule 14a-101) Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. _____)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 14A (Rule 14a-101) Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 14A (Rule 14a-101) Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. _____)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 14A (Rule 14a-101) Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 20, 2024 SeaStar Medical

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 20, 2024 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporation

SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216

SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 August 23, 2024 VIA EDGAR United States Securities and Exchange Commission Division of Corporation Finance 100 F.

SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216

SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 August 23, 2024 VIA EDGAR United States Securities and Exchange Commission Division of Corporation Finance 100 F.

SeaStar Medical Holding Corporation Up to $25 Million of Common Stock

Filed Pursuant to Rule 424(b)(5) Registration No. 333-275968 PROSPECTUS SUPPLEMENT (To Prospectus Dated December 8, 2023) SeaStar Medical Holding Corporation Up to $25 Million of Common Stock We have entered into an at the market offering agreement (the “Offering Agreement”), dated August 20, 2024, with H.C. Wainwright & Co., LLC, as sales agent (the “Sales Agent” or “Wainwright”), relating to the

At The Market Offering Agreement, dated August 20, 2024, by and between SeaStar Medical Holding Corporation, and H.C. Wainwright & Co., LLC (incorporated by reference to Exhibit 10.1 of Form 8-K filed by the registrant on August 21, 2024).

Exhibit 10.1 AT THE MARKET OFFERING AGREEMENT August 20, 2024 H.C. Wainwright & Co., LLC 430 Park Avenue New York, New York 10022 Ladies and Gentlemen: SeaStar Medical Holding Corporation, a corporation organized under the laws of Delaware (the “Company”), confirms its agreement (this “Agreement”) with H.C. Wainwright & Co., LLC (the “Manager”) as follows: 1. Definitions. The terms that follow, wh

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 20, 2024 SeaStar Medical H

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 20, 2024 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporation)

As filed with the Securities and Exchange Commission on August 16, 2024

As filed with the Securities and Exchange Commission on August 16, 2024 Registration No.

As filed with the Securities and Exchange Commission on August 16, 2024

As filed with the Securities and Exchange Commission on August 16, 2024 Registration No.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM TO Commission File Number 001-39927 SEASTAR MED

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 13, 2024 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporation)

SeaStar Medical Reports Second Quarter 2024 Financial Results and Provides a Business Update

Exhibit 99.1 SeaStar Medical Reports Second Quarter 2024 Financial Results and Provides a Business Update DENVER (August 13, 2024) – SeaStarMedical Holding Corporation (Nasdaq: ICU) (“SeaStar Medical” or the “Company”), a commercial-stage medical device company developing proprietary solutions to reduce the consequences of hyperinflammation on vital organs, reports financial results for the three

Filing Fee Table.

Exhibit 107 Calculation of Filing Fee Tables S-3 (Form Type) SeaStar Medical Holding Corporation (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered and Carry Forward Securities Security Type Security Class Title Fee Calculation or Carry Forward Rule Amount Registered Proposed Maximum Offering Price Per Unit (1) Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Carry Forward Form Type Carry Forward File Number Carry Forward Initial effective date Filing Fee Previously Paid In Connection with Unsold Securities to be Carried Forward Newly Registered Securities Fees to be Paid Equity Common Stock, par value $0.

As filed with the Securities and Exchange Commission on August 2, 2024

As filed with the Securities and Exchange Commission on August 2, 2024 Registration No.

Form of Common Stock Purchase Warrant (incorporated by reference to Exhibit 4.1 of Form 8-K filed by the registrant on July 11, 2024).

Exhibit 4.1 NEITHER THIS SECURITY NOR THE SECURITIES FOR WHICH THIS SECURITY IS EXERCISABLE HAVE BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE IN RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD EXCEPT PURSUANT TO AN EFFECTIVE REGISTR

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 10, 2024 SeaStar Medical Hol

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 10, 2024 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporation) (

Form of Placement Agent Warrant (incorporated by reference to Exhibit 4.2 of Form 8-K filed by the registrant on July 11, 2024).

Exhibit 4.2 NEITHER THIS SECURITY NOR THE SECURITIES FOR WHICH THIS SECURITY IS EXERCISABLE HAVE BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE IN RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD EXCEPT PURSUANT TO AN EFFECTIVE REGISTR

SeaStar Medical Announces Closing of $10 Million Registered Direct Offering Priced At-the-Market Under Nasdaq Rules

Exhibit 99.2 SeaStar Medical Announces Closing of $10 Million Registered Direct Offering Priced At-the-Market Under Nasdaq Rules DENVER (July 11, 2024) – SeaStar Medical Holding Corporation (Nasdaq: ICU) (SeaStar Medical) announces that it has closed its previously announced registered offering for the issuance and sale of an aggregate of 947,868 shares of its common stock at a purchase price of $

Securities Purchase Agreement (incorporated by reference to Exhibit 10.1 of Form 8-K filed by the registrant on July 11, 2024).

Exhibit 10.1 SECURITIES PURCHASE AGREEMENT This Securities Purchase Agreement (this “Agreement”) is dated as of July 10, 2024, between SeaStar Medical Holding Corporation, a Delaware corporation (the “Company”), and each purchaser identified on the signature pages hereto (each, including its successors and assigns, a “Purchaser” and collectively the “Purchasers”). WHEREAS, subject to the terms and

SeaStar Medical Holding Corporation 947,868 Shares of Common Stock

Filed Pursuant to Rule 424(b)(5) Registration No. 333-275968 PROSPECTUS SUPPLEMENT (To Prospectus Dated December 8, 2023) SeaStar Medical Holding Corporation 947,868 Shares of Common Stock Pursuant to this prospectus supplement and the accompanying prospectus, we are offering in a registered direct offering to certain purchasers 947,868 shares of our common stock, par value $0.0001 per share (“Com

SeaStar Medical Announces $10 Million Registered Direct Offering Priced At-the-Market Under Nasdaq Rules

Exhibit 99.1 SeaStar Medical Announces $10 Million Registered Direct Offering Priced At-the-Market Under Nasdaq Rules DENVER (July 10, 2024) – SeaStar Medical Holding Corporation (Nasdaq: ICU) (SeaStar Medical), today announced it has entered into a definitive agreement for the issuance and sale of an aggregate of 947,868 shares of its common stock (or common stock equivalents in lieu thereof) at

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 5, 2024 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporation) (C

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 3, 2024 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporation) (C

Form of Warrant to Purchase Common Stock dated August 7, 2023

Exhibit 4.9 Execution Version NEITHER THE ISSUANCE AND SALE OF THE SECURITIES REPRESENTED BY THIS CERTIFICATE NOR THE SECURITIES INTO WHICH THESE SECURITIES ARE EXERCISABLE HAVE BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR APPLICABLE STATE SECURITIES LAWS. THE SECURITIES MAY NOT BE OFFERED FOR SALE, SOLD, TRANSFERRED OR ASSIGNED (I) IN THE ABSENCE OF (A) AN EFFECTIVE REGISTRATI

Form of Warrant to Purchase Common Stock dated January 12, 2024

Exhibit 4.11 Execution Version NEITHER THE ISSUANCE AND SALE OF THE SECURITIES REPRESENTED BY THIS CERTIFICATE NOR THE SECURITIES INTO WHICH THESE SECURITIES ARE EXERCISABLE HAVE BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR APPLICABLE STATE SECURITIES LAWS. THE SECURITIES MAY NOT BE OFFERED FOR SALE, SOLD, TRANSFERRED OR ASSIGNED (I) IN THE ABSENCE OF (A) AN EFFECTIVE REGISTRAT

Filing Fee Table.

Exhibit 107 Calculation of Filing Fee Tables S-3 (Form Type) SeaStar Medical Holding Corporation (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered and Carry Forward Securities Security Type Security Class Title Fee Calculation or Carry Forward Rule Amount Registered Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Carry Forward Form Type Carry Forward File Number Carry Forward Initial effective date Filing Fee Previously Paid In Connection with Unsold Securities to be Carried Forward Newly Registered Securities Fees to be Paid Equity Common Stock, par value $0.

Form of Warrant to Purchase Common Stock dated December 11, 2023

Exhibit 4.10 Execution Version NEITHER THE ISSUANCE AND SALE OF THE SECURITIES REPRESENTED BY THIS CERTIFICATE NOR THE SECURITIES INTO WHICH THESE SECURITIES ARE EXERCISABLE HAVE BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR APPLICABLE STATE SECURITIES LAWS. THE SECURITIES MAY NOT BE OFFERED FOR SALE, SOLD, TRANSFERRED OR ASSIGNED (I) IN THE ABSENCE OF (A) AN EFFECTIVE REGISTRAT

Form of Placement Agent Warrant

Exhibit 4.13 Execution Version PLACEMENT AGENT COMMON STOCK PURCHASE WARRANT SEASTAR MEDICAL HOLDING CORPORATION Warrant Shares: 542,038 Issue Date: January 30, 2024 THIS PLACEMENT AGENT COMMON STOCK PURCHASE WARRANT (the “Warrant”) certifies that, for value received, MAXIM PARTNERS LLC or its assigns (the “Holder”) is entitled, upon the terms and subject to the limitations on exercise and the con

Form of Warrant to Purchase Common Stock dated January 24, 2024

Exhibit 4.12 Execution Version NEITHER THE ISSUANCE AND SALE OF THE SECURITIES REPRESENTED BY THIS CERTIFICATE NOR THE SECURITIES INTO WHICH THESE SECURITIES ARE EXERCISABLE HAVE BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR APPLICABLE STATE SECURITIES LAWS. THE SECURITIES MAY NOT BE OFFERED FOR SALE, SOLD, TRANSFERRED OR ASSIGNED (I) IN THE ABSENCE OF (A) AN EFFECTIVE REGISTRAT

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K/A (Amendment No. 2)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K/A (Amendment No. 2) (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM TO Commission File Number 001-3

Second Amendment to Securities Purchase Agreement, dated December 11, 2023, by and between the Company and 3i, LP

Exhibit 10.39 Execution Version SECOND AMENDMENT TO SECURITIES PURCHASE AGREEMENT This Second Amendment to Securities Purchase Agreement (this “Amendment”) dated as of December 11, 2023 (the “Effective Date”) is entered into by and between SeaStar Medical Holding Corporation, a Delaware corporation (the “Company”), and 3i, LP, a Delaware limited partnership (the “Purchaser”). RECITALS A. The Purch

Description of Securities

EXHIBIT 4.5 DESCRIPTION OF THE REGISTRANT’S SECURITIES REGISTERED PURSUANT TO SECTION 12 OF THE SECURITIES EXCHANGE ACT OF 1934 On October 28, 2022, LMF Merger Sub, Inc., a wholly owned subsidiary of LMF Acquisition Opportunities, Inc., (“LMAO”) merged with and into SeaStar Medical, Inc. (the "Business Combination"), with SeaStar Medical, Inc. surviving the Business Combination as a wholly owned s

As filed with the Securities and Exchange Commission on July 3, 2024

As filed with the Securities and Exchange Commission on July 3, 2024 Registration No.

Warrant Redemption Agreement, dated June 28, 2024, by and between SeaStar Medical Holding Corporation and an institutional investor (incorporated by reference to Exhibit 10.1 of Form 8-K filed by the registrant on July 2, 2024).

Exhibit 10.1 WARRANT REDEMPTION AGREEMENT June 28, 2024 This Warrant Redemption Agreement (this “Agreement”) is entered into by and between SeaStar Medical Holding Corporation (the “Company”) and 3i, LP or its assigns (the “Holder”). Reference is hereby made to the series of warrants set forth hereto on Annex A (the “Warrants”), to purchase shares of common stock, par value $0.001 per share (“Comm

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 28, 2024 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporation) (

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 24, 2024 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporation) (

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 6, 2024 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporation) (C

SeaStar Medical Strengthens Board of Directors and Transitions to Commercial-Stage Company

Exhibit 99.1 SeaStar Medical Strengthens Board of Directors and Transitions to Commercial-Stage Company DENVER (June x, 2024) – SeaStarMedical Holding Corporation (Nasdaq: ICU) (SeaStar Medical) announces that three new members have joined its Board of Directors. Two new directors, Jennifer A. Baird and Bernadette N. Vincent, were elected at the Company’s 2024 Annual Meeting of Stockholders held o

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 5, 2024 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporation) (C

SeaStar Medical Announces 25-for-1 Reverse Stock Split

Exhibit 99.1 SeaStar Medical Announces 25-for-1 Reverse Stock Split DENVER (June 6, 2024) – SeaStar Medical Holding Corporation(Nasdaq: ICU), a medical device company developing proprietary solutions to reduce the consequences of hyperinflammation on vital organs, announces the Company’s 25-for-1 reverse stock split, which will become effective at June 7, 2024 at 5:00 PM EDT. The Company’s common

Second Certificate of Amendment of Third Amended and Restated Certificate of Incorporation of SeaStar Medical Holding Corporation (incorporated by reference to Exhibit 3.1 to Form 8-K filed by the registrant on June 7, 2024).

Exhibit 3.1 Second Certificate of Amendment of Third Amended and Restated Certificate of Incorporation of SeaStar Medical Holding Corporation SeaStar Medical Holding Corporation (the “Corporation”), a corporation organized and existing under the General Corporation Law of the State of Delaware (the “DGCL”), does hereby certify as follows: FIRST: At the Effective Time, as defined below, each twenty

Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year, Material Modification to Rights of Security Holders, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 7, 2024 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporation) (C

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 04, 2024 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporation) (

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM TO Commission File Number 001-39927 SEASTAR ME

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 14, 2024 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporation) (C

SeaStar Medical Reports First Quarter 2024 Financial Results and Provides a Business Update

Exhibit 99.1 MAY 14, 2024 SeaStar Medical Reports First Quarter 2024 Financial Results and Provides a Business Update DENVER (May 14, 2024) – SeaStarMedical Holding Corporation (Nasdaq: ICU) (“SeaStar Medical” or the “Company”), a commercial-stage medical device company developing proprietary solutions to reduce the consequences of hyperinflammation on vital organs, reports financial results for t

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ______)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K/A (Amendment No. 1)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K/A (Amendment No. 1) (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM TO Commission File Number 001-3

SeaStar Medical Holding Corporation Compensation Recoupment Policy (incorporated by reference to Exhibit 97.1 of Form 10-K/A filed by the registrant on April 26, 2024).

DB2/ 46962994.3 EXHIBIT 97.1 SEASTAR MEDICAL HOLDING CORPORATION COMPENSATION RECOUPMENT POLICY I. Purpose. The Board of Directors (the “Board”) of SeaStar Medical Holding Corporation (the “Company”) has adopted this Compensation Recoupment Policy (this “Policy”) in order to implement a mandatory clawback policy in the event of a Restatement in compliance with Section 10D of the Exchange Act. Any

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. _____)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.

Second Amended and Restated Bylaws of SeaStar Medical Holding Corporation (incorporated by reference to Exhibit 3.1 of Form 8-K filed by the registrant on April 18, 2024).

Exhibit 3.1 SEASTAR MEDICAL HOLDING CORPORATION SECOND AMENDED AND RESTATED BY-LAWS Article I. — General. 1.1. Offices. The registered office of SeaStar Medical Holding Corporation (the “Company”) shall be in the City of Wilmington, County of New Castle, State of Delaware. The Company may also have offices at such other places both within and without the State of Delaware as the board of directors

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 12, 2024 SeaStar Medical Ho

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 12, 2024 SeaStar Medical Holding Corporation (Exact name of registrant as specified in its charter) Delaware 001-39927 85-3681132 (State or other jurisdiction of incorporation)

SeaStar Medical Reports 2023 Financial Results and Provides a Business Update

Exhibit 99.1 SeaStar Medical Reports 2023 Financial Results and Provides a Business Update DENVER (April 17, 2024) – SeaStar Medical Holding Corporation (Nasdaq: ICU) (“SeaStar Medical” or the “Company”), a commercial-stage medical device company developing proprietary solutions to reduce the consequences of hyperinflammation on vital organs, reports financial results for the 12 months ended Decem

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 17, 2024 SeaStar Medical Ho

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 17, 2024 SeaStar Medical Holding Corporation (Exact name of registrant as specified in its charter) Delaware 001-39927 85-3681132 (State or other jurisdiction of incorporation)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One)e ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM TO Commission File Number 001-39927 SEASTAR MEDICA

Amendment No. 1 to the License and Distribution Agreement, dated December 29, 2023, by and between the Company and Nuwellis, Inc.

Ex. 10.38 AMENDMENT NO. 1 TO LICENSE AND DISTRIBUTION AGREEMENT This AMENDMENT NO. 1 TO LICENSE AND DISTRIBUTION AGREEMENT (“Amendment”) is effective as of December 29, 2023 (“Amendment Effective Date”) between SeaStar Medical Holding Corporation, a Delaware corporation, with a place of business at 3513 Brighton Blvd, Suite 410, Denver, Colorado 80216 (“Supplier”) and Nuwellis, Inc., a Delaware co

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 12b-25 NOTIFICATION OF LATE FILING

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 12b-25 NOTIFICATION OF LATE FILING OMB APPROVAL OMB Number: 3235-0058 Expires: April 30, 2025 Estimated average burden hours per response ............ 2.50 SEC File Number: 001-39927 CUSIP Number: 502015100 (Check one): ý Form 10-K o Form 20-F o Form 11-K o Form 10-Q o Form 10-D o Form N-CEN o Form N-CSR For Period Ended:

SeaStar Medical to Restate Financials, Sets Business Update Call for April 17 Restatement of non-cash items is not expected to materially impact cash position or operations

Exhibit 99.1 SeaStar Medical to Restate Financials, Sets Business Update Call for April 17 Restatement of non-cash items is not expected to materially impact cash position or operations DENVER (March 27, 2024) – SeaStar Medical Holding Corporation (Nasdaq: ICU), a commercial-stage medical device company developing proprietary solutions to reduce the consequences of hyperinflammation on vital organ

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K/A CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K/A CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 27, 2024 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporation

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 27, 2024 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporation)

SeaStar Medical to Restate Financials, Sets Business Update Call for April 17 Restatement of non-cash items is not expected to materially impact cash position or operations

Exhibit 99.1 SeaStar Medical to Restate Financials, Sets Business Update Call for April 17 Restatement of non-cash items is not expected to materially impact cash position or operations DENVER (March 27, 2024) – SeaStar Medical Holding Corporation (Nasdaq: ICU), a commercial-stage medical device company developing proprietary solutions to reduce the consequences of hyperinflammation on vital organ

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K DRAFT CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K DRAFT CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 21, 2024 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorpora

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 6, 2024 SeaStar Medical Hol

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 6, 2024 SeaStar Medical Holding Corporation (Exact name of registrant as specified in its charter) Delaware 001-39927 85-3681132 (State or other jurisdiction of incorporation) (

SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 32 (to the Prospectus dated January 4, 2023)

Prospectus Supplement No. 32 Filed Pursuant to Rule 424(b)(3) File No. 333-268503 SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 32 (to the Prospectus dated January 4, 2023) This Prospectus Supplement No. 32 supplements and amends the prospectus dated January 4, 2023, as amended by Prospectus Supplement No. 1 dated Februa

SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 31 (to the Prospectus dated January 4, 2023)

Prospectus Supplement No. 31 Filed Pursuant to Rule 424(b)(3) File No. 333-268503 SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 31 (to the Prospectus dated January 4, 2023) This Prospectus Supplement No. 31 supplements and amends the prospectus dated January 4, 2023, as amended by Prospectus Supplement No. 1 dated Februa

SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 26 (to the Prospectus dated January 4, 2023)

Prospectus Supplement No. 26 Filed Pursuant to Rule 424(b)(3) File No. 333-268503 SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 26 (to the Prospectus dated January 4, 2023) This Prospectus Supplement No. 26 supplements and amends the prospectus dated January 4, 2023, as amended by Prospectus Supplement No. 1 dated Februa

SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 25 (to the Prospectus dated January 4, 2023)

Prospectus Supplement No. 25 Filed Pursuant to Rule 424(b)(3) File No. 333-268503 SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 25 (to the Prospectus dated January 4, 2023) This Prospectus Supplement No. 25 supplements and amends the prospectus dated January 4, 2023, as amended by Prospectus Supplement No. 1 dated Februa

SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 29 (to the Prospectus dated January 4, 2023)

Prospectus Supplement No. 29 Filed Pursuant to Rule 424(b)(3) File No. 333-268503 SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 29 (to the Prospectus dated January 4, 2023) This Prospectus Supplement No. 29 supplements and amends the prospectus dated January 4, 2023, as amended by Prospectus Supplement No. 1 dated Februa

SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 27 (to the Prospectus dated January 4, 2023)

Prospectus Supplement No. 27 Filed Pursuant to Rule 424(b)(3) File No. 333-268503 SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 27 (to the Prospectus dated January 4, 2023) This Prospectus Supplement No. 27 supplements and amends the prospectus dated January 4, 2023, as amended by Prospectus Supplement No. 1 dated Februa

SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 35 (to the Prospectus dated January 4, 2023)

Prospectus Supplement No. 35 Filed Pursuant to Rule 424(b)(3) File No. 333-268503 SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 35 (to the Prospectus dated January 4, 2023) This Prospectus Supplement No. 35 supplements and amends the prospectus dated January 4, 2023, as amended by Prospectus Supplement No. 1 dated Februa

SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 21 (to the Prospectus dated January 4, 2023)

Prospectus Supplement No. 21 Filed Pursuant to Rule 424(b)(3) File No. 333-268503 SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 21 (to the Prospectus dated January 4, 2023) This Prospectus Supplement No. 21 supplements and amends the prospectus dated January 4, 2023, as amended by Prospectus Supplement No. 1 dated Februa

SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 23 (to the Prospectus dated January 4, 2023)

Prospectus Supplement No. 23 Filed Pursuant to Rule 424(b)(3) File No. 333-268503 SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 23 (to the Prospectus dated January 4, 2023) This Prospectus Supplement No. 23 supplements and amends the prospectus dated January 4, 2023, as amended by Prospectus Supplement No. 1 dated Februa

SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 24 (to the Prospectus dated January 4, 2023)

Prospectus Supplement No. 24 Filed Pursuant to Rule 424(b)(3) File No. 333-268503 SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 24 (to the Prospectus dated January 4, 2023) This Prospectus Supplement No. 24 supplements and amends the prospectus dated January 4, 2023, as amended by Prospectus Supplement No. 1 dated Februa

SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 33 (to the Prospectus dated January 4, 2023)

424B3 1 seastar424b3.htm PROSPECTUS SUPPLEMENT NO. 33 Prospectus Supplement No. 33 Filed Pursuant to Rule 424(b)(3) File No. 333-268503 SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 33 (to the Prospectus dated January 4, 2023) This Prospectus Supplement No. 33 supplements and amends the prospectus dated January 4, 2023,

SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 28 (to the Prospectus dated January 4, 2023)

Prospectus Supplement No. 28 Filed Pursuant to Rule 424(b)(3) File No. 333-268503 SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 28 (to the Prospectus dated January 4, 2023) This Prospectus Supplement No. 28 supplements and amends the prospectus dated January 4, 2023, as amended by Prospectus Supplement No. 1 dated Februa

SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 34 (to the Prospectus dated January 4, 2023)

Prospectus Supplement No. 34 Filed Pursuant to Rule 424(b)(3) File No. 333-268503 SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 34 (to the Prospectus dated January 4, 2023) This Prospectus Supplement No. 34 supplements and amends the prospectus dated January 4, 2023, as amended by Prospectus Supplement No. 1 dated Februa

SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 20 (to the Prospectus dated January 4, 2023)

Prospectus Supplement No. 20 Filed Pursuant to Rule 424(b)(3) File No. 333-268503 SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 20 (to the Prospectus dated January 4, 2023) This Prospectus Supplement No. 20 supplements and amends the prospectus dated January 4, 2023, as amended by Prospectus Supplement No. 1 dated Februa

SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 30 (to the Prospectus dated January 4, 2023)

Prospectus Supplement No. 30 Filed Pursuant to Rule 424(b)(3) File No. 333-268503 SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 30 (to the Prospectus dated January 4, 2023) This Prospectus Supplement No. 30 supplements and amends the prospectus dated January 4, 2023, as amended by Prospectus Supplement No. 1 dated Februa

SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 22 (to the Prospectus dated January 4, 2023)

Prospectus Supplement No. 22 Filed Pursuant to Rule 424(b)(3) File No. 333-268503 SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 22 (to the Prospectus dated January 4, 2023) This Prospectus Supplement No. 22 supplements and amends the prospectus dated January 4, 2023, as amended by Prospectus Supplement No. 1 dated Februa

FDA Grants Humanitarian Device Exemption Approval to SeaStar Medical’s Selective Cytopheretic Device for Pediatric Acute Kidney Injury SCD-PED (Pediatric) is the first FDA-approved product in the Company’s Quelimmune™ product family

Exhibit 99.1 FDA Grants Humanitarian Device Exemption Approval to SeaStar Medical’s Selective Cytopheretic Device for Pediatric Acute Kidney Injury SCD-PED (Pediatric) is the first FDA-approved product in the Company’s Quelimmune™ product family DENVER (February 22, 2024) – SeaStar Medical Holding Corporation (Nasdaq: ICU), a medical device company developing proprietary solutions to reduce the co

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 21, 2024 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporatio

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 15, 2024 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporatio

US81256L1044 / SEASTAR MEDICAL HOLDING CORP A / Vellar Opportunities Fund Master, Ltd. Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 13G/A Under the Securities Exchange Act of 1934 (Amendment No.

SEASTAR MEDICAL HOLDING CORP. 3513 Brighton Blvd, Suite 410 Denver, CO 80216 February 12, 2024

SEASTAR MEDICAL HOLDING CORP. 3513 Brighton Blvd, Suite 410 Denver, CO 80216 February 12, 2024 VIA EDGAR Correspondence United States Securities and Exchange Commission Division of Corporation Finance Office of Industrial Applications and Services 100 F Street, N.E. Washington, D.C. 20549 Attention: Juan Grana Re: Acceleration of Effective Date SeaStar Medical Holding Corporation Registration Stat

* * * * * *

Morgan, Lewis & Bockius LLP 1400 Page Mill Road Palo Alto, CA 94304 Tel. +1.650.843.4000 Fax: +1.650.843.4001 www.morganlewis.com Albert Lung Partner +1.650.843.7263 [email protected] February 9, 2024 VIA EDGAR AS CORRESPONDENCE United States Securities and Exchange Commission Division of Corporation Finance Office of Industrial Applications and Services 100 F Street, N.E. Washington, D.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 06, 2024 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporatio

As filed with the Securities and Exchange Commission on February 9, 2024

As filed with the Securities and Exchange Commission on February 9, 2024 Registration No.

As filed with the Securities and Exchange Commission on February 9, 2024

As filed with the Securities and Exchange Commission on February 9, 2024 Registration No.

CALCULATION OF FILING FEE TABLES Form S-8 (Form Type) SeaStar Medical Holding Corporation (Exact Name of Registrant as Specified in Its Charter) Table 1 – Newly Registered Securities

Exhibit 107 CALCULATION OF FILING FEE TABLES Form S-8 (Form Type) SeaStar Medical Holding Corporation (Exact Name of Registrant as Specified in Its Charter) Table 1 – Newly Registered Securities Security Type Security Class Title Fee Calculation Rule Amount Registered (1) Proposed Maximum Offering Price per Unit (2) Maximum Aggregate Offering Price Fee Rate Amount Registration Fee Equity Common Stock, $0.

Placement Agency Agreement, dated January 26, 2024, by and among the Company and Maxim Group LLC (incorporated by reference to Exhibit 1.1 of Form 8-K dated January 30, 2024).

Exhibit 1.1 PLACEMENT AGENCY AGREEMENT January 26, 2024 Maxim Group LLC 300 Park Avenue, 16th Floor New York, NY 10022 Ladies and Gentlemen: Subject to the terms and conditions herein (this “Agreement”), SeaStar Medical Holding Corporation, a Delaware corporation (the “Company”), hereby agrees to sell up to an aggregate of $8,999,999.78 of registered and unregistered securities, including, but not

Form of Pre-Funded Warrant to Purchase Common Stock (incorporated by reference to Exhibit 4.1 of Form 8-K dated January 30, 2024).

Exhibit 4.1 PRE-FUNDED COMMON STOCK PURCHASE WARRANT SEASTAR MEDICAL HOLDING CORPORATION Warrant Shares: Initial Exercise Date: , 2024 THIS PRE-FUNDED COMMON STOCK PURCHASE WARRANT (the “Warrant”) certifies that, for value received, or its assigns (the “Holder”) is entitled, upon the terms and subject to the limitations on exercise and the conditions hereinafter set forth, at any time on or after

Form of Series B Common Stock Purchase Warrant to Purchase Common Stock (incorporated by reference to Exhibit 4.3 of Form 8-K dated January 30, 2024).

Exhibit 4.3 NEITHER THIS SECURITY NOR THE SECURITIES FOR WHICH THIS SECURITY IS EXERCISABLE HAVE BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE IN RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD EXCEPT PURSUANT TO AN EFFECTIVE REGISTR

Form of Securities Purchase Agreement, by and among the Company and the parties thereto (incorporated by reference to Exhibit 10.1 of Form 8-K filed January 30, 2024).

Exhibit 10.1 SECURITIES PURCHASE AGREEMENT This Securities Purchase Agreement (this “Agreement”) is dated as of January , 2024, between SeaStar Medical Holding Corporation, a Delaware corporation (the “Company”), and each purchaser identified on the signature pages hereto (each, including its successors and assigns, a “Purchaser” and collectively the “Purchasers”). WHEREAS, subject to the terms an

6,304,545 Shares of Common Stock Pre-Funded Warrants to Purchase 4,536,216 Shares of Common Stock 4,536,216 Shares of Common Stock Underlying the Pre-Funded Warrants SeaStar Medical Holding Corporation

Filed Pursuant to Rule 424(b)(5) Registration No. 333-275968 Prospectus Supplement (to Prospectus dated December 22, 2023) 6,304,545 Shares of Common Stock Pre-Funded Warrants to Purchase 4,536,216 Shares of Common Stock 4,536,216 Shares of Common Stock Underlying the Pre-Funded Warrants SeaStar Medical Holding Corporation We are offering 6,304,545 shares (the “Shares”) of our common stock, par va

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 26, 2024 SeaStar Medical

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 26, 2024 SeaStar Medical Holding Corporation (Exact name of registrant as specified in its charter) Delaware 001-39927 85-3681132 (State or other jurisdiction of incorporation

# # #

Exhibit 99.1 SeaStar Medical Announces Pricing of $9.0 Million Registered Direct Offering Priced At-the-Market DENVER (January 26, 2024) – SeaStar Medical Holding Corporation (Nasdaq: ICU), a medical technology company developing proprietary solutions to reduce the consequences of hyperinflammation on vital organs, announced today that it has entered into a securities purchase agreement with a sin

Form of Series A Common Stock Purchase Warrant to Purchase Common Stock (incorporated by reference to Exhibit 4.2 of Form 8-K dated January 30, 2024).

Exhibit 4.2 NEITHER THIS SECURITY NOR THE SECURITIES FOR WHICH THIS SECURITY IS EXERCISABLE HAVE BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE IN RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD EXCEPT PURSUANT TO AN EFFECTIVE REGISTR

As filed with the Securities and Exchange Commission on January 24, 2024

As filed with the Securities and Exchange Commission on January 24, 2024 Registration No.

Second Amendment to Securities Purchase Agreement, dated December 11, 2023, by and between the registrant and 3i, LP.

Exhibit 10.7 Execution Version SECOND AMENDMENT TO SECURITIES PURCHASE AGREEMENT This Second Amendment to Securities Purchase Agreement (this “Amendment”) dated as of December 11, 2023 (the “Effective Date”) is entered into by and between SeaStar Medical Holding Corporation, a Delaware corporation (the “Company”), and 3i, LP, a Delaware limited partnership (the “Purchaser”). RECITALS A. The Purcha

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 24, 2024 SeaStar Medical

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 24, 2024 SeaStar Medical Holding Corporation (Exact name of registrant as specified in its charter) Delaware 001-39927 85-3681132 (State or other jurisdiction of incorporation

Filing Fee Table.

Exhibit 107 Calculation of Filing Fee Tables S-3 (Form Type) SeaStar Medical Holding Corporation (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered and Carry Forward Securities Security Type Security Class Title Fee Calculation or Carry Forward Rule Amount Registered Proposed Maximum Offering Price Per Unit (1) Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Carry Forward Form Type Carry Forward File Number Carry Forward Initial effective date Filing Fee Previously Paid In Connection with Unsold Securities to be Carried Forward Newly Registered Securities Fees to be Paid Equity Common Stock, par value $0.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 12, 2024 SeaStar Medical

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 12, 2024 SeaStar Medical Holding Corporation (Exact name of registrant as specified in its charter) Delaware 001-39927 85-3681132 (State or other jurisdiction of incorporation

SeaStar Medical Appoints David A. Green as Chief Financial Officer

Exhibit 99.1 SeaStar Medical Appoints David A. Green as Chief Financial Officer DENVER (January 11, 2024) – SeaStar Medical Holding Corporation (Nasdaq: ICU), a medical device company developing proprietary solutions to reduce the consequences of hyperinflammation on vital organs, announces the appointment of healthcare industry veteran David A. Green as Chief Financial Officer, effective January

Employment Agreement, dated January 10, 2024, by and between the Company and David Green (incorporated by reference to Exhibit 10.1 to Form 8-K dated January 11, 2024).

Exhibit 10.1 EMPLOYMENT AGREEMENT This EMPLOYMENT AGREEMENT (the “Agreement”) is made as of January 10, 2024 (the “Effective Date”) by and between SeaStar Medical Holding Corporation. (the “Company”), a Delaware corporation, and David Green (“Executive”). WHEREAS, the Company desires to secure the services and employment of Executive on behalf of the Company, and Executive desires to be so employe

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 10, 2024 SeaStar Medical

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 10, 2024 SeaStar Medical Holding Corporation (Exact name of registrant as specified in its charter) Delaware 001-39927 85-3681132 (State or other jurisdiction of incorporation

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 27, 2023 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporatio

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 20, 2023 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporatio

SEASTAR MEDICAL HOLDING CORP. 3513 Brighton Blvd, Suite 410 Denver, CO 80216 December 20, 2023

SEASTAR MEDICAL HOLDING CORP. 3513 Brighton Blvd, Suite 410 Denver, CO 80216 December 20, 2023 VIA EDGAR Correspondence United States Securities and Exchange Commission Division of Corporation Finance Office of Industrial Applications and Services 100 F Street, N.E. Washington, D.C. 20549 Attention: Abby Adams Re: Acceleration of Effective Date SeaStar Medical Holding Corporation Registration Stat

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 13, 2023 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporatio

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 11, 2023 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporatio

As filed with the Securities and Exchange Commission on December 11, 2023

As filed with the Securities and Exchange Commission on December 11, 2023 Registration No.

Filing Fee Table.

Exhibit 107 Calculation of Filing Fee Tables S-3 (Form Type) SeaStar Medical Holding Corporation (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered and Carry Forward Securities Security Type Security Class Title Fee Calculation or Carry Forward Rule Amount Registered (1) Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Carry Forward Form Type Carry Forward File Number Carry Forward Initial effective date Filing Fee Previously Paid In Connection with Unsold Securities to be Carried Forward Newly Registered Securities Fees to be Paid Equity Common Stock, par value $0.

As filed with the Securities and Exchange Commission on December 8, 2023

As filed with the Securities and Exchange Commission on December 8, 2023 Registration No.

As filed with the Securities and Exchange Commission on December 7, 2023

As filed with the Securities and Exchange Commission on December 7, 2023 Registration No.

SEASTAR MEDICAL HOLDING CORP. 3513 Brighton Blvd, Suite 410 Denver, CO 80216 December 7, 2023

SEASTAR MEDICAL HOLDING CORP. 3513 Brighton Blvd, Suite 410 Denver, CO 80216 December 7, 2023 VIA EDGAR Correspondence United States Securities and Exchange Commission Division of Corporation Finance Office of Industrial Applications and Services 100 F Street, N.E. Washington, D.C. 20549 Attention: Conlon Danberg Re: Acceleration of Effective Date SeaStar Medical Holding Corporation Registration S

Filing Fee Table.

Exhibit 107 Calculation of Filing Fee Tables S-3 (Form Type) SeaStar Medical Holding Corporation (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered and Carry Forward Securities Security Type Security Class Title Fee Calculation or Carry Forward Rule Amount Registered Proposed Maximum Offering Price Per Unit (1) Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Carry Forward Form Type Carry Forward File Number Carry Forward Initial effective date Filing Fee Previously Paid In Connection with Unsold Securities to be Carried Forward Newly Registered Securities Fees to be Paid Equity Common Stock, par value $0.

As filed with the Securities and Exchange Commission on December 1, 2023

As filed with the Securities and Exchange Commission on December 1, 2023 Registration No.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 28, 2023 SeaStar Medical

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 28, 2023 SeaStar Medical Holding Corporation (Exact name of registrant as specified in its charter) Delaware 001-39927 85-3681132 (State or other jurisdiction of incorporatio

Letter from Armanino LLP to the Securities and Exchange Commission dated November 29, 2023.

Exhibit 16.1 November 29, 2023 Securities and Exchange Commission 100 F Street, N.E. Washington, D.C. 20549 Commissioners: We have read Item 4.01 of the Current Report on Form 8-K of SeaStar Medical Holding Corporation dated November 29, 2023, which we understand will be filed with the Securities and Exchange Commission, and we agree with the statements concerning our firm contained in such Form 8

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 27, 2023 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporatio

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 21, 2023 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporatio

SeaStar Medical Reports Third Quarter 2023 Financial Results and Provides a Business Update

SeaStar Medical Reports Third Quarter 2023 Financial Results and Provides a Business Update DENVER (November 14, 2023) – SeaStar Medical Holding Corporation (Nasdaq: ICU) (“SeaStar Medical” or the “Company”), a medical device company developing proprietary solutions to reduce the consequences of hyperinflammation on vital organs, reports financial results for the three and nine months ended September 30, 2023 and provides a business update.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM TO Commission File Number 001-39927 SEASTA

FDA Issues Approvable Letter for SeaStar Medical’s Selective Cytopheretic Device for Pediatric Patients

FDA Issues Approvable Letter for SeaStar Medical’s Selective Cytopheretic Device for Pediatric Patients DENVER October 30, 2023 – SeaStar Medical Holding Corporation (Nasdaq: ICU), a medical device company developing proprietary solutions to reduce the consequences of dysregulated immune responses including hyperinflammation on vital organs, announces that the U.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 30, 2023 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporation

SeaStar Medical Holding Corporation

SeaStar Medical Holding Corporation 3513 Brighton Blvd., Suite 410 Denver, CO 80216 VIA EDGAR United States Securities and Exchange Commission 100 F. Street, NW Washington, DC 20549 Re: SeaStar Medical Holding Corporation Withdrawal of Registration Statement on Form S-1 File No. 333-274413 Dear Ladies and Gentlemen: Pursuant to Rule 477 under the Securities Act of 1933, as amended (the “Securities

SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 19 (to the Prospectus dated January 4, 2023)

Prospectus Supplement No. 19 Filed Pursuant to Rule 424(b)(3) File No. 333-268503 SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 19 (to the Prospectus dated January 4, 2023) This Prospectus Supplement No. 19 supplements and amends the prospectus dated January 4, 2023, as amended by Prospectus Supplement No. 1 dated Februa

SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 8 (to the Prospectus dated August 10, 2023)

Prospectus Supplement No. 8 Filed Pursuant to Rule 424(b)(3) File No. 333-273359 SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 8 (to the Prospectus dated August 10, 2023) This Prospectus Supplement No. 8 supplements and amends the prospectus dated August 10, 2023, as amended by Prospectus Supplement No. 1 dated August 15

SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 14 (to the Prospectus dated April 24, 2023)

Prospectus Supplement No. 14 Filed Pursuant to Rule 424(b)(3) File No. 333-271215 SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 14 (to the Prospectus dated April 24, 2023) This Prospectus Supplement No. 14 supplements and amends the prospectus dated April 24, 2023, as amended by Prospectus Supplement No. 1 dated May 10,

SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 19 (to the Prospectus dated January 20, 2023)

Prospectus Supplement No. 19 Filed Pursuant to Rule 424(b)(3) File No. 333-269338 SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 19 (to the Prospectus dated January 20, 2023) This Prospectus Supplement No. 19 supplements and amends the prospectus dated January 20, 2023, as amended by Prospectus Supplement No. 1 dated Febr

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 03, 2023 SeaStar Medical Holding Corporation (Exact name of Registrant as Specified in Its Charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporation

SeaStar Medical Provides Regulatory Update Regarding Selective Cytopheretic Device Use in Pediatric Acute Kidney Injury Under a Humanitarian Device Exemption Company to finalize labeling with FDA Approvable Letter expected within a month

SeaStar Medical Provides Regulatory Update Regarding Selective Cytopheretic Device Use in Pediatric Acute Kidney Injury Under a Humanitarian Device Exemption Company to finalize labeling with FDA Approvable Letter expected within a month DENVER (October 3, 2023) – SeaStar Medical Holding Corporation (Nasdaq: ICU), a medical device company developing proprietary solutions to reduce the consequences of dysregulated immune responses including hyperinflammation on vital organs, announces receipt of a correspondence from the U.

SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 13 (to the Prospectus dated April 24, 2023)

Prospectus Supplement No. 13 Filed Pursuant to Rule 424(b)(3) File No. 333-271215 SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 13 (to the Prospectus dated April 24, 2023) This Prospectus Supplement No. 13 supplements and amends the prospectus dated April 24, 2023, as amended by Prospectus Supplement No. 1 dated May 10,

SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 7 (to the Prospectus dated August 10, 2023)

Prospectus Supplement No. 7 Filed Pursuant to Rule 424(b)(3) File No. 333-273359 SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 7 (to the Prospectus dated August 10, 2023) This Prospectus Supplement No. 7 supplements and amends the prospectus dated August 10, 2023, as amended by Prospectus Supplement No. 1 dated August 15

SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 18 (to the Prospectus dated January 4, 2023)

Prospectus Supplement No. 18 Filed Pursuant to Rule 424(b)(3) File No. 333-268503 SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 18 (to the Prospectus dated January 4, 2023) This Prospectus Supplement No. 18 supplements and amends the prospectus dated January 4, 2023, as amended by Prospectus Supplement No. 1 dated Februa

SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 18 (to the Prospectus dated January 20, 2023)

Prospectus Supplement No. 18 Filed Pursuant to Rule 424(b)(3) File No. 333-269338 SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 18 (to the Prospectus dated January 20, 2023) This Prospectus Supplement No. 18 supplements and amends the prospectus dated January 20, 2023, as amended by Prospectus Supplement No. 1 dated Febr

SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 17 (to the Prospectus dated January 20, 2023)

Prospectus Supplement No. 17 Filed Pursuant to Rule 424(b)(3) File No. 333-269338 SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 17 (to the Prospectus dated January 20, 2023) This Prospectus Supplement No. 17 supplements and amends the prospectus dated January 20, 2023, as amended by Prospectus Supplement No. 1 dated Febr

Current Report

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 26, 2023 SeaStar Medical Holding Corporation (Exact name of registrant as specified in its charter) Delaware 001-39927 85-3681132 (State or Other Jurisdiction of Incorporati

SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 12 (to the Prospectus dated April 24, 2023)

Prospectus Supplement No. 12 Filed Pursuant to Rule 424(b)(3) File No. 333-271215 SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 12 (to the Prospectus dated April 24, 2023) This Prospectus Supplement No. 12 supplements and amends the prospectus dated April 24, 2023, as amended by Prospectus Supplement No. 1 dated May 10,

SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 6 (to the Prospectus dated August 10, 2023)

Prospectus Supplement No. 6 Filed Pursuant to Rule 424(b)(3) File No. 333-273359 SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 6 (to the Prospectus dated August 10, 2023) This Prospectus Supplement No. 6 supplements and amends the prospectus dated August 10, 2023, as amended by Prospectus Supplement No. 1 dated August 15

SeaStar Medical Holding Corporation 3513 Brighton Blvd, Suite 410 Denver, CO 80216 (844) 427-8100 Prospectus Supplement No. 17 (to the Prospectus dated January 4, 2023)

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