TETRA TECH INC 8-K

What Happened

• Tetra Tech, Inc. announced on January 6, 2026 (8-K filing and press release) that Roger R. Argus will succeed Dan L. Batrack as Chief Executive Officer effective February 19, 2026 (the company’s annual shareholder meeting). Dan L. Batrack, currently Chairman and CEO, will transition to Executive Chairman of the Board and is expected to serve in that role for a minimum of two years.

Key Details

• Effective date: February 19, 2026 (annual shareholder meeting).
• New CEO: Roger R. Argus — joined Tetra Tech more than 30 years ago; served as President since October 2025.
• Outgoing CEO/Chair: Dan L. Batrack will continue as Executive Chairman and remain involved in leadership.
• Argus prior roles include Executive Vice President, Corporate Development (Nov 2024–Oct 2025); President, Commercial/International Services Group (Oct 2023–Oct 2025); Senior VP & President, Government Services Group (Oct 2018–Oct 2024); President, U.S. Government Division (Oct 2017–Nov 2024).
• The company disclosed there are no special arrangements, family relationships, or related-party transactions requiring Item 404 disclosure.
• A press release announcing the change was issued January 6, 2026 (filed as Exhibit 99.1).

Why It Matters

• Leadership transitions at the CEO level are material for investors because they can affect company strategy, execution and market perception. This appointment is an internal succession from a long-tenured executive (Roger Argus), with the outgoing CEO staying on as Executive Chairman for at least two years—providing continuity while enabling new operational leadership. Investors should note the effective date (Feb 19, 2026) and any future communications from the company about strategic or operational changes under the new CEO.