The National Environmental Policy Act (NEPA) process begins when a federal agency develops a proposal to take a major federal action. These actions are defined in NEPA (42 United States Code [U.S.C.] Sections 4321 et seq.), as amended by Public Law 118-5 and the Fiscal Responsibility Act of 2023, and the Department of War (DoW) NEPA Implementing Procedures, effective July 1, 2025. Learn more here: National Environmental Policy Act Review Process | US EPA.