As part of our oversight of assistance agreement awards made by the U.S. Environmental Protection Agency (EPA), the EPA's Office of Inspector General (OIG) examined the costs claimed under Cooperative Agreement No. 2A-00T13801 awarded to the California Air Resources Board (CARB). The OIG conducted the examination to determine whether the costs claimed under the cooperative agreement were reasonable, allowable and allocable in accordance with the Code of Federal Regulations (CFR) under 40 CFR Part 31, Uniform Administrative Requirements for Grants and Cooperative Agreements to State and Local Governments; 2 CFR Part 225, Cost Principles for State, Local, and Indian Tribal Governments (Office of Management and Budget Circular A-87); and the terms and conditions of the cooperative agreement.