Results of Operations and Financial Condition. On August 13, 2026, Nuwellis, Inc. (the “Company”) issued a press release reporting its financial results for the three and six months ended June 30, 2026. A copy of the press release is attached hereto as Exhibit 99.1 and is incorporated herein by reference. In accordance with General Instruction B.2 of Form 8-K, the information included in this Current Report on Form 8-K (including Exhibit 99.1) is furnished pursuant to

Entry into a Material Definitive Agreement. Securities Purchase Agreement On July 31, 2026, Nuwellis, Inc. (the “ Company ”) entered into a securities purchase agreement (the “ Purchase Agreement ”) with certain accredited investors (the “ Purchasers ”), pursuant to which the Company agreed to issue and sell to such investor in a registered direct offering (the “ Registered Offering ”) an aggregate of 1,310,890 shares (the “ Shares ”) of common stock, par value $0.0001 per share (the “ Common…

Unregistered Sales of Equity Securities. The information set forth in

Material Modification to Rights of Security Holders. ​ To the extent required by

CEO — John L. Erb: John L. Erb resigned as CEO but continues to serve as Chairman of the Board, and Michael McCormick was appointed as the new CEO.

Results of Operations and Financial Condition. On May 12, 2026, Nuwellis, Inc. (the “Company”) issued a press release reporting its financial results for the three months ended March 31, 2026. A copy of the press release is attached hereto as Exhibit 99.1 and is incorporated herein by reference. In accordance with General Instruction B.2 of Form 8-K, the information included in this Current Report on Form 8-K (including Exhibit 99.1) is furnished pursuant to

Director — Mika Grasso and Katharyn Field: Both directors resigned from the Board with disagreements noted.

Director — Mika Grasso and Katharyn Field: Both directors resigned due to disagreements with the company, alleging failures in information provision and other issues.

Other Events. On March 17, 2026, Nuwellis, Inc. (the “ Company ”) announced the closing of its previously announced acquisition of Rendiatech, Inc., an Israeli-based developer of automated kidney function monitoring technology designed to support clinical decision-making in critically ill patients. SIGNATURES Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized. Da…

Results of Operations and Financial Condition. On March 10, 2026, Nuwellis, Inc. (the “Company”) issued a press release reporting its financial results for the three and twelve months ended December 31, 2025. A copy of the press release is attached hereto as Exhibit 99.1 and is incorporated herein by reference. In accordance with General Instruction B.2 of Form 8-K, the information included in this Current Report on Form 8-K (including Exhibit 99.1) is furnished pursuant to

Results of Operations and Financial Condition. On November 12, 2025, Nuwellis, Inc. (the “Company”) issued a press release reporting its financial results for the three and nine months ended September 30, 2025. A copy of the press release is attached hereto as Exhibit 99.1 and is incorporated herein by reference. In accordance with General Instruction B.2 of Form 8-K, the information included in this Current Report on Form 8-K (including Exhibit 99.1) is furnished pursuant to

Chief Financial Officer — Robert B. Scott: The CFO resigned and the company has not yet named a permanent successor.

Entry into a Material Definitive Agreement. On September 3, 2025, the Company entered into an At The Market Offering Agreement (the “ Sales Agreement ”) with Ladenburg Thalmann & Co. Inc. (“ Ladenburg ”) pursuant to which the Company may sell shares of the Company’s common stock, par value $0.0001 (the “ Common Stock ”), from time to time, at its option, through or to Ladenburg, as sales agent or principal. Sales of the Company’s Common Stock made pursuant to the Sales Agreement, if any, will…

Other Events. On August 19, 2025, Nuwellis, Inc. (the “ Company ”) announced that it has entered into a non-binding letter of intent to acquire Rendiatech, Ltd., an Israeli-based medical device company specializing in real-time urine flow and acute kidney injury monitoring technologies. The proposed acquisition is expected to support the Company’s strategy to expand its current technology platform beyond ultrafiltration by potentially adding continuous renal health monitoring technologies tha…

Results of Operations and Financial Condition. On August 14, 2025, Nuwellis, Inc. (the “Company”) issued a press release reporting its financial results for the three and six months ended June 30, 2025. A copy of the press release is attached hereto as Exhibit 99.1 and is incorporated herein by reference. In accordance with General Instruction B.2 of Form 8-K, the information included in this Current Report on Form 8-K (including Exhibit 99.1) is furnished pursuant to

Chief Executive Officer and President — John L. Erb: John L. Erb was promoted from interim CEO to permanent CEO and President.

Material Modification to Rights of Security Holders. ​ To the extent required by

Notice of Delisting or Failure to Satisfy a Continued Listing Rule or Standard; Transfer of Listing. ​ On June 18, 2025, Nuwellis, Inc. (the “Company” ) received a letter (the “Deficiency Notice” ) from the Listing Qualifications Department (the “Staff” ) of the Nasdaq Stock Market ( “Nasdaq” ) informing the Company that because the closing bid price for the Company’s common stock listed on Nasdaq was below $1.00 for 30 consecutive trading days, the Company is not in compliance with the minim…

Entry into a Material Definitive Agreement. The information included in

Unregistered Sales of Equity Securities. The information included in

Results of Operations and Financial Condition. On May 13, 2025, Nuwellis, Inc. (the “Company”) issued a press release reporting its financial results for the three months ended March 31, 2025. A copy of the press release is attached hereto as Exhibit 99.1 and is incorporated herein by reference. In accordance with General Instruction B.2 of Form 8-K, the information included in this Current Report on Form 8-K (including Exhibit 99.1) is furnished pursuant to

Entry into a Material Definitive Agreement. On May 9, 2025 (the “ Effective Date ”), Nuwellis, Inc. (the “ Company ”) entered into a Supply & Quality Agreement (the “ Supply Agreement ”) with Kluge Design, LLC, a Minnesota limited liability company (“ KDI ”), pursuant to which KDI will manufacture the Aquadex Blood Circuit, Aquadex dELC Catheter and Aquadex SmartFlow Console (the “ Aquadex ”) and perform related calibration and repair services. The Company will retain exclusive ownership of t…

Results of Operations and Financial Condition. On March 11, 2025, Nuwellis, Inc. (the “Company”) issued a press release reporting its financial results for the three and twelve months ended December 31, 2024. A copy of the press release is attached hereto as Exhibit 99.1 and is incorporated herein by reference. In accordance with General Instruction B.2 of Form 8-K, the information included in this Current Report on Form 8-K (including Exhibit 99.1) is furnished pursuant to

President and Chief Executive Officer — Nestor Jaramillo, Jr.: Mr. Nestor Jaramillo, Jr. is retiring from the Company and has been succeeded by John L. Erb as Interim Chief Executive Officer.

Other Events. On December 11, 2024, Nuwellis, Inc. (the “ Company ”) sent a notice to affected customers that it is voluntarily recalling specific lots of the AquaFlexFlow UF 500 Plus extracorporeal blood circuit which is used with the Aquadex Smartflow® or Aquadex FlexFlow® System. The lots are being recalled due to failures of the blood circuit associated with too many mismatch alarms. The blood circuits may indicate “Ultrafiltrate Weight Mismatch” or “Excessive Weight Mismatch” alarms whil…