NEWS RELEASE November 11, 2026 Tetra Tech Reports Strong Fourth Quarter and Fiscal Year 2026 Results Pasadena, California. Tetra Tech, Inc. (NASDAQ: TTEK), a global provider of high-end technical and engineering services, Leading with Science in water, environment and sustainable infrastructure, today announced results for the fourth quarter and fiscal year ended September 27, 2026. Exhibit 99.1 Fourth Quarter Results Revenue and revenue, net of subcontractor costs (net revenue), in the fourth quarter total ...