X0202 SCHEDULE 13D/A 0001548312 XXXXXXXX LIVE 12 Common Stock, par value $0.001 per share 06/25/2026 false 0001210708 443787205 Star Equity Holdings, Inc. 53 FOREST AVENUE, SUITE 101 OLD GREENWICH CT 06870 JEFFREY E. EBERWEIN 203-489-9500 53 Forest Avenue, Suite 101 Old Greenwich CT 06870 0001548312 N JEFFREY E. EBERWEIN PF OO N X1 1149289.00 1149289.00 1149289.00 N 30.7 IN * Includes 49,450 shares of common stock underlying immediately exercisable warrants ("Warrants") to purchase Star common stock. Excludes certain grants made under the Issuer's 2009 Incentive Stock and Awards Plan, as amended and restated, specifically 8,918 shares of restricted stock granted on September 15, 2025, 5,703 shares of restricted stock granted on January 15, 2026, 6,504 shares of restricted stock granted on April 15, 2026, and 6,750 restricted stock units granted on January 24, 2025, which vest upon the anniversary of the respective grant dates. Common Stock, par value $0.001 per share Star Equity Holdings, Inc. 53 FOREST AVENUE, SUITE 101 OLD GREENWICH CT 06870 The following constitutes Amendment No. 12 to the Schedule 13D filed by the undersigned ("Amendment No. 12"). This Amendment No. 12 amends the Schedule 13D as specifically set forth herein. Item 3 is hereby amended and restated as follows: The aggregate purchase price of the 1,149,289 Shares beneficially owned by Mr. Eberwein is approximately $22,560,917, excluding brokerage commissions. In addition to the 1,149,289 Shares, Mr. Eberwein owns 765,077 shares of the Issuer's 10% Series A Cumulative Perpetual Preferred Stock. Item 4 is hereby amended to add the following: On June 25, 2026 Mr. Eberwein (the "Seller") entered into a Rule 10b5-1 of the Securities Exchange Act of 1934 ("Exchange Act") Sales Trading Plan ("10b5-1 Sales Plan") with Ladenburg Thalmann & Co. ("Broker") for the purpose of establishing a trading plan to effect sales of shares of Series A Cumulative Perpetual Preferred Stock, par value $0.001 per share, ("Preferred Stock") of the Issuer in compliance with all applicable laws, including, without limitation, Section 10(b) of the Exchange Act and the rules and regulations promulgated thereunder, including, but not limited to, Rule 10b5-1. The Broker is authorized to begin selling Preferred Stock pursuant to the 10b5-1 Sales Plan on October 1, 2026. The 10b5-1 Sales Plan expires on October 1, 2028, unless terminated earlier under certain conditions. There can be no assurance as to how many preferred shares, if any, will be sold pursuant to the 10b5-1 Sales Plan or at what price any such shares of Preferred Stock will be sold. The Seller may in the future modify, amend, suspend, or terminate the 10b5-1 Sales Plan in its sole discretion, and the Seller does not undertake any obligation to disclose any such modification, amendment, suspension, or termination. Notwithstanding, the Broker shall not sell Preferred Stock under the 10b5-1 Sales Plan, while the Broker is selling Preferred Stock as sales agent for the Issuer's ATM offering program. A copy of the 10b5-1 Sales Plan is attached hereto as Exhibit 99.2 and is incorporated herein by reference. Items 5(a)-(c) are hereby amended and restated to read as follows: The aggregate percentage of Shares reported owned by the Reporting Person is based upon 3,748,404 Shares, which is inclusive of 3,698,954 shares outstanding as of June 29, 2026 in addition to 49,450 Warrants attributed to the Reporting Person. The total number of Shares outstanding is based on information provided by the Issuer to the Reporting Person. As of the close of business on June 29, 2026, Mr. Eberwein beneficially owned 1,149,289 Shares. Percentage: 30.66% 1. Sole power to vote or direct vote: 1,149,289 2. Shared power to vote or direct vote: 0 3. Sole power to dispose or direct the disposition: 1,149,289 4. Shared power to dispose or direct the disposition: 0 Jeff Eberwein's transactions in the Shares since the last Schedule 13D/A filed on June 1, 2026 are set forth in Schedule A, attached hereto as Exhibit 99.1, and is incorporated herein by reference. Exhibit 99.1 - Schedule A; Exhibit 99.2 - Rule 10b5-1 Sales Trading Plan, dated June 25, 2026, by and between Jeffrey E. Eberwein and Ladenburg Thalmann & Co. JEFFREY E. EBERWEIN /s/ Jeffrey E. Eberwein Jeffrey E. Eberwein 06/29/2026