Type	Name	Date
Indenture	Indenture, by and between Tetra Tech, Inc. and U.S. Bank Trust Company, National Association, as Trustee	08/22/2023
Credit agreement	Amendment No. 1 to Third Amended and Restated Credit Agreement among Tetra Tech, Inc., Tetra Tech Canada Holding Corporation, Tetra Tech UK Holdings Limited, Tetra Tech Coffey Pty Ltd, the subsidiary guarantors and the lenders party thereto and Bank of America, N.A., as administrative agent	08/22/2023
Credit agreement	Amendment No. 2 to Third Amended and Restated Credit Agreement among Tetra Tech, Inc., Tetra Tech Canada Holding Corporation, Tetra Tech UK Holdings Limited, Tetra Tech Coffey Pty Ltd, the subsidiary guarantors and the lenders party thereto and Bank of America, N.A., as administrative agent	08/22/2023
Credit agreement	Bridge Credit Agreement	09/26/2022
Credit agreement	Amendment No. 2 to Second Amended and Restated Credit Agreement among Tetra Tech, Inc., Tetra Tech Canada Holding Corporation, Tetra Tech UK Holdings Limited, Tetra Tech Coffey Pty., Ltd., the subsidiary guarantors and the lenders party thereto and Bank of America, N.A., as Administrative Agent	02/22/2022
Credit agreement	Second Amended and Restated Credit Agreement among Tetra Tech, Inc., Tetra Tech Canada Holding Corporation, Coffey UK Limited, Coffey Services Australia Pty. Ltd., the lenders party thereto and Bank of America, N.A., as Administrative Agent	08/01/2018
Credit agreement	Amendment No. 1 to the Amended and Restated Credit Agreement among Tetra Tech, Inc., Tetra Tech Canada Holding Corporation, the lenders party thereto and Bank of America, N.A., as Administrative Agent	09/30/2013
Credit agreement	Amended and Restated Credit Agreement among Tetra Tech, Inc., Tetra Tech Canada Holding Corporation, the lenders party thereto and Bank of America, N.A., as Administrative Agent	05/09/2013
Credit agreement	Credit Agreement, among the Registrant, certain subsidiaries of the Registrant, Bank of America, N.A., as Administrative Agent, and the other lenders party thereto	03/30/2011