[Form 3] Tecogen Inc. Initial Statement of Beneficial Ownership

Rhea-AI Filing Summary

Tecogen (OTCQX:TGEN) submitted a routine Form 3 – Initial Statement of Beneficial Ownership on 29 Jun 2025 for newly reported insider Stephen Lafaille, VP of Business Development.

The filing shows Mr Lafaille directly holds 400 common shares and three option grants covering an aggregate 108,862 shares:

• 6,362 options @ $3.93, fully vested, expiring 04/29/2026
• 50,000 options @ $0.71, performance-vested on adjusted EBITDA targets, expiring 07/09/2030
• 52,500 options @ $1.10, time-vested 50% per year, expiring 01/21/2032

No purchase, sale, or other material corporate event is disclosed; the document fulfills Section 16(a) reporting requirements and has no immediate operational or financial impact on Tecogen.

SEC Form 3

FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0104
Estimated average burden
hours per response:			0.5

1. Name and Address of Reporting Person^*

Lafaille Stephen

(Last) (First) (Middle)

76 TREBLE COVE ROAD

(Street)

NORTH BILLERICA MA 01862

(City) (State) (Zip)

2. Date of Event Requiring Statement (Month/Day/Year)
04/23/2024

3. Issuer Name and Ticker or Trading Symbol
TECOGEN INC. [ TGEN ]

4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	VP of Business Development

5. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)
Common Stock	400	D

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Stock Options (Right to Buy)	04/29/2017(1)	04/29/2026	Common Stock	6,362	$3.93	D
Stock Options (Right to Buy)	(2)	07/09/2030	Common Stock	50,000	$0.71	D
Stock Options (Right to Buy)	01/21/2023(3)	01/21/2032	Common Stock	52,500	$1.1	D

Explanation of Responses:

1. Fully vested

2. Vests 50% upon achievement of Adjusted EBITDA goal of 2% of revenue in two consecutive quarters, and 50% upon achievement of Adjusted EBITDA goal of 3% of revenue in four consecutive quarters

3. Vests 50% per year

Remarks:

	/s/ Stephen Lafaille	06/24/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 5 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What insider holdings did TGEN disclose in the June 29 2025 Form 3?

Tecogen reported that VP Stephen Lafaille owns 400 common shares and 108,862 stock options with exercise prices between $0.71 and $3.93.

Does this Form 3 filing signal any material change for Tecogen investors?

No. It is a routine ownership disclosure required by the SEC and does not affect Tecogen’s operations, strategy, or financial condition.