Joining the United States military requires that you meet certain requirements, including that you are a U.S. citizen. Some branches, such as the Army, allow permanent resident aliens to join. Height and weight requirements, physical fitness requirements and health requirements also apply. Additionally, each branch of the military has specific age requirements.
The U.S. Army accepts enlistees who are 17 to 35 years old. In most cases, you must be in your senior year of high school or have graduated from high school to join. The Army accepts people who have passed the general educational development (GED) test. Candidates to become a warrant officer must be between 18 and 33 with a valid high school diploma. Specialized testing is also required. Most commissioned Army officer candidates must be 18 to 35 to enroll when Officer Candidate School begins, but waivers are sometimes provided.
The U.S. Navy accepts enlisted personnel with a valid high school diploma or GED who are 17 to 34 years old at the beginning of boot camp. High school students can join the Delayed Entry Program, but won't be able to report to boot camp until after graduation. Officers, including commissioned and warrant officers, must be U.S. citizens who are 19 to 35 years old with a valid four-year college degree. Age waivers are sometimes available for positions in high demand.
The U.S. Marine Corps accepts candidates for enlisted positions who are 17 to 29 years old. Unlike other branches of the military, the Marine Corps doesn't accept people with a GED. The age limits for officers in the Marine Corps depend on the specific job; however, the only candidate accepted will be one who has a four-year degree or is working toward her degree when she signs up.
The U.S. Air Force only accepts applicants for enlisted positions who are between 17 and 27 years old. An applicant who is near the upper age limit must report to boot camp before his 28th birthday. Officer candidates must be at least 17 and able to be commissioned before turning 35 years old. An enlistee joining the Air Force as part of the medical program must meet age requirements that vary according to the position he is filling.
The U.S. Coast Guard accepts enlisted personnel who are at least 17 years old but not older than 27. People with prior military service may join the Coast Guard until they turn 29; however, if specialized training in an "A" school is required, the age limit is 32 years. The Coast Guard doesn't usually accept GEDs, but exceptions are sometimes made for those joining who will fill certain high-demand jobs.