Tetra Tech has set January 28, 2026, after market close, for the release of its first quarter 2026 financial results, followed by a live conference call on January 29, 2026, at 8:00 a.m. Pacific Time. Investors can access the audio-visual webcast via a link on the Company’s Investor Relations page. The replay will remain available on tetratech.com/investors. This scheduling continues the Company’s disciplined quarterly reporting cadence, reflecting its commitment to transparency as it addresses complex water, environmental and sustainable infrastructure challenges worldwide with more than 25,000 employees.

Effective February 19, 2026, Roger Argus will succeed Dan Batrack as Chief Executive Officer concurrent with Tetra Tech’s annual shareholders meeting, and will join the Board of Directors. Mr. Argus, a 30-year veteran of the Company and most recently President, has driven major water, infrastructure and environmental programs and led integration of strategic acquisitions that expanded Tetra Tech’s global footprint. Mr. Batrack, CEO for over two decades and Board Chairman since 2008, will transition to Executive Chairman for at least two years, leveraging his stewardship to support long-term strategy for a firm that now generates approximately $5 billion in annual revenue. Lead Independent Director Kirsten Volpi highlighted the rigorous succession planning that underpins this change and underscores confidence in sustaining Tetra Tech’s performance trajectory.