Uniformed services of the United States The United States of America has seven federal uniformed services that commission officers as defined by Title 10 , and subsequently structured and organized by Title 10 , Title 14 , Title 33 and Title 42 of the United States Code . Uniformed services . The seven uniformed services are , in order of precedence by ceremonial formation : Each of the uniformed services is administratively headed by a federal executive department and its corresponding civilian Cabinet leader . Federal executive departments . United States Department of Defense ( DOD ) . Note : The order of precedence within the U . S . Department of Defense is set by DOD Directive 1005 . 8 and is not dependent on the date of creation by the U . S . Congress . United States Department of Homeland Security ( DHS ) . Note : The U . S . Coast Guard was a part of the U . S . Department of Transportation from 1967 to 2002 . Prior to 1967 , it was a part of the U . S . Department of the Treasury . Statutory definition . The seven uniformed services are defined by : The five uniformed services that make up the United States Armed Forces are defined in the previous clause : Armed forces . Five of the uniformed services make up the U . S . armed forces , four of which are within the U . S . Department of Defense . The Coast Guard is part of the Department of Homeland Security and has both military and law enforcement duties . Title 14 states that the Coast Guard is part of the military at all times , making it the only branch of the military outside the Department of Defense . During a declared state of war , however , the President or Congress may direct that the Coast Guard operate as part of the Navy . The U . S . Public Health Service Commissioned Corps , along with the NOAA Commissioned Corps , operate under military rules with the exception of the applicability of the Uniform Code of Military Justice , to which they are subject only when militarized by executive order or while detailed to any component of the armed forces . Reserve components of the United States armed forces are all members of the military . The National Guard is a reserve military force composed of state National Guard militia units , which operate under Title 32 and under state authority . The National Guard was first formed in the Colony of Virginia in 1607 and is the oldest uniformed military force founded in the New World . The National Guard can be mobilized by the President to operate under Federal authority through Title 10 . When acting under federal direction , the National Guard of the United States is managed by the National Guard Bureau , which is a joint activity under the Department of Defense , with a general in the Army or Air Force as its top leader . The National Guard of the United States serves as a reserve component for both the Army and the Air Force and can be called up for federal active duty in times of war or national emergencies . Noncombatant uniformed services . Commissioned officers of NOAA and PHS wear uniform s that are derived from U . S . Navy uniforms , except that the commissioning devices , buttons , and insignia reflect their specific service . Uniformed officers of NOAA and PHS are paid on the same scale as members of the armed services with respective rank and time - in - grade . Additionally , PHS Officers are covered by the Uniformed Services Employment and Reemployment Act and the Service Members Civil Relief Act ( formerly the Soldiers and Sailors Civil Relief Act ) . Furthermore , all seven Uniformed Services are subject to the provisions of 10 USC 1408 , the Uniformed Services Former Spouses Protection Act ( USFSPA ) . Both noncombatant uniformed services ( PHS & NOAA ) consist of commissioned officer s only and have no warrant ranks or enlisted ranks . Commissioned officers of the Public Health Service and of the National Oceanic and Atmospheric Administration can be militarized by the President of the United States . Statutory authorization to militarize the Public Health Service is under Title 42 U . S . C . ( Based on rank , commissioned officers of the Public Health Service ( USPHS ) and NOAA can be classified as Category III , IV , and V under the Geneva Convention ) . The U . S . Coast and Geodetic Survey ( a predecessor to NOAA ) originally began commissioning its officers so that if captured while engaged in battlefield surveying , they could not legally be tried as spies . The Public Health Service ( PHS ) traces its origins to a system of marine hospitals created " for the relief of sick and disabled seamen " by the U . S . Congress in 1798 ; it adopted a military model of organization in 1871 .