TETRA TECH INC

We include in our backlog only those contracts for which funding has been provided and work authorization has been received. We estimate that approximately 70% of our backlog at the end of fiscal 2025 will be recognized as revenue in fiscal

2026, as work is being performed. However, we cannot guarantee that the revenue projected in our backlog will be realized or, if realized, will result in profits. In addition, project cancellations or scope adjustments may occur with respect to contracts reflected in our backlog. For example, certain of our contracts with the U.S. federal government and other clients are terminable at the discretion of the client, with or without cause. These types of backlog reductions could adversely affect our revenue and margins. Accordingly, our backlog as of any particular date is an uncertain indicator of our future earnings.

Our backlog at fiscal 2025 year-end was $4.1 billion. GSG and CIG reported $1.98 billion and $2.22 billion of backlog, respectively, at fiscal 2025 year-end.