A rear admiral in the uniformed services of the United States is either of two different ranks of commissioned officers: one-star flag officers and two-star flag officers. By contrast, in most other countries, the term "rear admiral" refers only to an officer of two-star rank.

The United States Public Health Service Commissioned Corps is the uniformed service branch of the United States Public Health Service and one of the eight uniformed services of the United States. The commissioned corps' primary mission is the protection, promotion, and advancement of health and safety of the general public.