The Department of the Navy (DoN) is revising portions of its internal regulations that establish the responsibilities and procedures for complying with the National Environmental Policy Act (NEPA). Agencies can define and exclude from further review categories of such activities, called categorical exclusions (CATEXs), in their NEPA implementing procedures as a way to reduce unnecessary paperwork and delay. This revision clarifies when certain DoN actions must be studied to determine their effect on the human environment and what types of activities fall under CATEXs are excluded from the NEPA analysis and documentation requirements.