---
schema_version: "secwatch.filing_event.v1"
accession: "0001537435-23-000116"
form_type: "8-K"
ticker: "TGEN"
cik: "0001537435"
company_name: "TECOGEN INC."
filed_at: "2023-09-26T23:59:59+00:00"
generated_at: "2026-06-10T08:39:58.087878+00:00"
event_type: "leadership"
sentiment: "neutral"
materiality_score: 0.35
calibrated_materiality_score: 0.35
confidence: "high"
source: SEC EDGAR
---

# Tecogen appoints Susan Hirsch to board; receives option for 100,000 shares

## Summary
- Appointed Susan B. Hirsch as independent non-employee director to fill a board vacancy.
- Hirsch has over 40 years of investment management experience; formerly MD at Nuveen managing $20B+ in assets.
- Received a non-qualified stock option to purchase 100,000 shares under the 2022 Stock Incentive Plan.
- Hirsch and spouse jointly hold 245,416 shares of Tecogen common stock.
- Also serves on the board of Agenus Inc. and as Trustee for the Baruch College Fund.

## SEC filing metadata
- accession: 0001537435-23-000116
- form_type: 8-K
- ticker: TGEN
- cik: 0001537435
- company_name: TECOGEN INC.
- filed_at: 2023-09-26T23:59:59+00:00
- event_type: leadership
- sentiment: neutral
- materiality_score: 0.35
- calibrated_materiality_score: 0.35
- confidence: high
- sec_items: 5.02, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1537435/000153743523000116/0001537435-23-000116-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1537435/000153743523000116/tgen-20230922.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001537435-23-000116
- JSON: https://secwatch.observer/filing/0001537435-23-000116.json
- Plain text: https://secwatch.observer/filing/0001537435-23-000116.txt

## Key facts
- Executive change
  Susan B. Hirsch was appointed as independent non-employee director at TECOGEN INC..
  - Action: appointed
  - Role: independent non-employee director
  source text: On September 22, 2023, the Board of Directors of Tecogen Inc. (“registrant”) appointed Ms. Susan B. Hirsch to serve as an independent non-employee director of registrant to fill a vacancy in registrant’s board of directors.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1537435/000153743523000116/0001537435-23-000116-index.htm

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.