X0508 4 2026-02-06 0 0000831641 TETRA TECH INC TTEK 0001277150 BURDICK STEVEN M 3475 EAST FOOTHILL BOULEVARD PASADENA, CA 91107 0 1 0 0 EVP, CFO 0 COMMON STOCK 2026-02-06 4 G 0 11100 0 D 138251 D Bona fide gift to charitable organization. No compensation was given to the donor for the gifting of shares. The balance of 149,351 shares includes 132 shares of common stock that were acquired by the Reporting Person on December 15, 2025, pursuant to the Tetra Tech, Inc. Employee Stock Purchase Plan (ESPP). /s/ Preston Hopson, Attorney-in-fact for Steven M. Burdick 2026-02-06