Item 5.02. Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers. In February 2025, Mr. Robert A. Panora, President and COO of Tecogen Inc. (the “ Company”), increased his time commitment to the Company to full time in order to address operational matters associated with anticipated growth opportunities for the Company. Mr. Panora has performed services on a reduced work schedule since January 2020. In view of the foregoing, on March 6, 2025, the Company’s Compensation Committee agreed to increase Mr. Panora’s base compensation from $164,800 to $200,000 per year. In January 2025, the Company also hired an experienced Manufacturing Manager to focus on increasing manufacturing throughput. On February 14, 2025, Mr. Joseph E. Gehret, formerly Vice President of Operations, left the Company to pursue another opportunity. Pursuant to the terms of a consulting agreement effective February 15, 2025, Mr. Gehret agreed to remain available, for up to one year, for consultations with Company management from time to time. SIGNATURES Pursuant to the requirements of the Securities Exchange Act of 1934, the Company has duly caused this report to be signed on its behalf by the undersigned, hereunto duly authorized. TECOGEN INC. By: /s/ Abinand Rangesh March 10, 2025 Abinand Rangesh, Chief Executive Officer