Employee Count History - Tetra Tech, Inc.
Historical employee count data from SEC filings.
Workforce Trend Analysis
Employee Count History
SEC Filing History
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| Filing Date | Period | Employee Count | Form Type | YoY Change |
|---|---|---|---|---|
| Nov 20, 2025 | Sep 28, 2025 | 25,000 | 10-K | -16.67% |
| Nov 19, 2024 | Sep 29, 2024 | 30,000 | 10-K | +11.11% |
| Nov 22, 2023 | Oct 1, 2023 | 27,000 | 10-K | +28.57% |
| Nov 25, 2022 | Oct 2, 2022 | 21,000 | 10-K | 0.00% |
| Nov 24, 2021 | Oct 3, 2021 | 21,000 | 10-K | +5.00% |
| Nov 23, 2020 | Sep 27, 2020 | 20,000 | 10-K | 0.00% |
Nov 29, 2019 | Sep 29, 2019 | — | — | — |
Nov 16, 2018 | Sep 30, 2018 | — | — | — |
Nov 20, 2017 | Oct 1, 2017 | — | — | — |
Nov 22, 2016 | Oct 2, 2016 | — | — | — |
Nov 20, 2015 | Sep 27, 2015 | — | — | — |
Nov 19, 2014 | Sep 28, 2014 | — | — | — |
Nov 20, 2013 | Sep 29, 2013 | — | — | — |
Nov 15, 2012 | Sep 30, 2012 | — | — | — |
Nov 17, 2011 | Oct 2, 2011 | — | — | — |
Nov 16, 2010 | Oct 3, 2010 | — | — | — |
Nov 16, 2009 | Sep 27, 2009 | — | — | — |
Nov 19, 2008 | Sep 28, 2008 | — | — | — |
Nov 27, 2007 | Sep 30, 2007 | — | — | — |
Dec 28, 2006 | Oct 1, 2006 | — | — | — |
Dec 16, 2005 | Oct 2, 2005 | — | — | — |
Jan 3, 2005 | Oct 3, 2004 | — | — | — |
Dec 16, 2003 | Sep 28, 2003 | — | — | — |
Dec 30, 2002 | Sep 29, 2002 | — | — | — |
Dec 31, 2001 | Sep 30, 2001 | — | — | — |
Dec 29, 2000 | Oct 1, 2000 | — | — | — |
Dec 30, 1999 | Oct 3, 1999 | — | — | — |
Dec 31, 1998 | Oct 4, 1998 | — | — | — |
Dec 29, 1997 | Sep 28, 1997 | — | — | — |
Dec 30, 1996 | Sep 29, 1996 | — | — | — |