Rear admiral (United States)

A rear admiral in four of the uniformed services of the United States is one of two distinct ranks of commissioned officers; "rear admiral (lower half)," a one-star flag officer, and "rear admiral" (sometimes referred to as "rear admiral (upper half)"), a two-star flag officer. The two ranks are only utilized by the United States Navy, U.S. Coast Guard, U.S. Public Health Service Commissioned Corps, and the National Oceanographic and Atmospheric Administration Commissioned Officer Corps. In contrast, in most other nations' rank-bearing services, the term "rear admiral" refers exclusively to two-star flag officer rank.