ACAT IV
ACAT IV (Army, Navy and Marine Corps only) ACAT programs not otherwise designated as ACAT III are designated ACAT IV in accordance with Service policy. Decisions are made at the lowest appropriate level. There are two categories of ACAT IV programs in the Navy and Marine Corps: IVT (Test) and IVM (Monitor). ACAT IVT programs require Operational Test and Evaluation (OT&E) while ACAT IVM programs do not.