TECOGEN INC. — Form 8-K

Tecogen is filing a Form S-3 registration statement to permit resale of common stock by certain stockholders who acquired shares in exempt transactions. A form lock-up agreement template is attached, imposing a 182-calendar-day restriction on selling stockholders (trustees of trusts) from the effective date of the registration, with narrow exceptions for transfers to beneficiaries, divorce orders, Rule 10b5-1 plans established pre-lockup, and third-party offers for all outstanding stock. The filing contains no dollar amounts, share counts, or identified counterparties—only the boilerplate agreement structure.