Uniform Code of Military Justice Law and Legal Definition

The Uniform Code of Military Justice (UCMJ) is a federal law, enacted by Congress. The UCMJ is the foundation of military law in the U.S. The law governs the state military forces when not in federal service.

The president prescribes rules and procedures to implement the provisions of the UCMJ through the Manual for Courts-Martial, an executive order containing detailed instructions for implementing military law for the U.S. armed forces.