Exeter serves a broad range of organizations, including the following recent clients:
- Arkansas Public Service Commission
- Colorado River Commission of Nevada
- Delaware Public Service Commission
- Hawaii Public Utilities Commission
- Illinois Citizens Utility Board
- Indiana Office of Utility Consumer Counselor
- Louisiana Public Service Commission
- Maine Office of the Public Advocate
- Maine Public Utilities Commission
- Maryland Department of the Environment
- Maryland Energy Administration
- Maryland People’s Counsel
- Maryland Power Plant Research Program
- Maryland Public Service Commission
- New Hampshire Office of Consumer Advocate
- Office of the Ohio Consumers’ Counsel
- Ohio Public Utilities Commission
- Pennsylvania Office of Consumer Advocate
- Rhode Island Division of Public Utilities & Carriers
- Tennessee Attorney General