join the military

How Old Do You Have to Be to Join the Military

We know that people of all ages join the military, but what is the actual earliest age you can join? For many, the obvious response would be 18 years of age, but that isn’t entirely true. With parental permission, it is possible to join the military at the age of 17. 

That said, the average age of a member of the United States military is 27 years old

Over time the age of those who join the military has changed, and in general, regulations have made recruits older and older. In the civil war era, there were children joining, even up to WWII we have records of at least one 12-year-old joining the military. 

Do People Lie About Their Age to Get Into the Military?

While it is rare, there have been cases of individuals falsifying records or lying about their age in order to join during times of war. This often occurs in the days before modern record-keeping when it was more difficult to keep such individuals out because no one would prove what they were saying was false. 

It should be noted that just because the minimum age to enlist in the military is 17 does not mean you can’t become involved earlier. Participating in events, speaking to recruiters and other activities are open to children who are much younger than 17. If you want to get involved, simply speak to your local army recruiter or other branch recruiters about opportunities. 

Maximum Age To Join the Military 

There is also a maximum age that is set by each of the service branches. For the US military that age cap is set by the type of service and which branch you will participate in. Let’s break this down so you can get a better idea of what the maximum age for joining is. 

The branch with the youngest maximum age is the Marine Corps. To be a marine you can join no later than your 29th year. That is both for active and reserve components as well, which could be due to the physical difficulty in becoming a marine, among other factors. 

Second lowest age maximum set for any military service

The Navy sets the maximum age limit at 34 years old for active duty and 39 years old for reserve duty. This is the second-lowest age maximum set for any military service. The maximum for the reserve component is about the same as the other branches of the service. 

In the US Army, you can join up to the age of 35. This applies to the regular army as well as the Reserves and National Guard element of the army. The ages are kept the same due to the physical requirements of being in the Army and the possibility of injury to an older individual. 

The Air Force is the least strict with the maximum age, and the only one that has a lower average age for reserves. To be in the Air Force as an active-duty airman, you can be as old as 39, and this applies to the Air National Guard as well. The age for Reservists is 38 years old. 

Requirements To Join the U.S. Miliatry 

Age rules aren’t the only requirements to join the military. You will also have to be capable and able to pass a variety of mental and physical tests. For instance, your height-to-body mass index has to be in certain ranges in order to qualify for service, and there are several other restrictions. 

A lot of these specifications are unique to each service, but speaking in general terms they do share commonalities. 

US Citizen 

To start with you have to be a US citizen or a permanent resident with a verified Green Card. Foreigners who wish to join the US military must first live in the United States and have a valid Green Card. There may also be additional restrictions placed on the type of work you can do if you’re not a US citizen. 

Physical Fitness 

You will be expected to perform basic physical tasks in a satisfactory measure. Each branch has its own standards, but all have a physical performance evaluation as part of their joining criteria. Typical activities involve jogging, climbing, push-ups, and sit-ups. 

There is a basic level expected when you join the military, as well as other levels expected once you’ve completed training. Being able to perform all of these activities in a reasonable way demonstrates the level of physical fitness required to join the military. 

Mental Evaluation 

There is a required minimum score on the ASVAB test. This test is designed to get an idea of what you know and how you apply this knowledge. In general, the Air Force has the highest requirements on average. 

This test will also determine what you are able to sign up for in each branch of the service. For instance, it requires a higher score to be an analyst than it does to be an infantryman. Due to the number of technical jobs is why the Air Force is considered as having the highest intellectual standards. 


With only a few, rare exceptions you are required to have a basic high school diploma or if you took a GED then that would work too. This is done to ensure that every soldier no matter what position they’re in has a basic grasp of our world and what’s in it. 

Medical and Mental Health 

There are various medical and mental health standards that must be met. These standards exist so that the branch you’re joining knows that you’re capable of undergoing and completing military training. Every branch of the US military also looks for upright, moral behavior and characteristics. 

Military Training and Age 

While it has changed throughout the years, the modern military stands firmly behind the decision to restrict the age of joining to 18 years. With parental or guardian consent that age can be lowered to 17, as long as high school has been completed. 

In our world, you can’t join the military, be a police officer, or engage in a vast number of professions until you reach a certain age. If you like learning about age-restricted activities and professions, or have additional information about age-related activities, contact us