The maximum age to join the U.S. military varies by branch, but generally ranges from about 28 to 42 years old for active duty enlistment:
- Army: 17 to 35 years old (officers must commission before age 31; age waivers possible, especially for prior service)
- Marine Corps: 17 to 28 years old
- Navy: 17 to 41 years old
- Air Force: 17 to 39 or 42 years old, depending on role; some specialties allow up to 48
- Coast Guard: 17 to 41 years old
- Space Force: 17 to 42 years old
In some cases, age waivers are available, especially for prior military service or critical roles, which can extend eligibility beyond these limits
. For example, a veteran can subtract prior years of service from their age to qualify for reenlistment
. While the typical cutoff for enlistment is mid to late 30s or early 40s, individuals over 40 or even 45 generally cannot join active duty, though some reserve or specialized roles might have higher limits or exceptions
. In summary, "too old" to join the military depends on the branch and circumstances, but generally, if you are older than about 35 to 42 years (depending on branch), you are beyond the standard enlistment age unless you qualify for a waiver or prior service exception
