If you have obtained a medical degree, you can become a military doctor by enlisting in the armed forces. Another route you take if you're already enlisted is to let the military help you get into medical school, and then become a military doctor afterward.
If you want to become a combat medic, you can qualify for that field without a college degree, provided you can complete the necessary training.
Qualifying to Serve
The U.S. military wants the best recruits it can get. No matter what path you follow to become a military doctor, you'll have to meet the military's requirements. Doctors in the Army Medical Corps, for instance, are commissioned officers. To qualify, you have to pass the Army physical fitness test, meet height and weight requirements, and the military's ethical standards. Rather than going to basic training, you must complete an Officer Basic Leadership Course.
Doctor to Military Doctor
If you're already a licensed doctor, you can enlist in the military, provided you meet the physical and other requirements. The military healthcare system is big with openings for all kinds of specialists, including endocrinologists, flight surgeons, dermatologists and etc. The military also employs regular family practitioners and dentists.
If you're not up for committing to a military career, becoming a reservist is another option. If you join the Navy Reserves, for instance, you train part-time every month, then serve two weeks a year. You still have to meet military requirements: Navy Reserve doctors must be over 21 and under 47, though older doctors with years of expertise sometimes receive waivers.
Medical Degree Preparatory Program
Military members with a bachelor's degree and 3.2 GPA can sign up for the Enlisted to Medical Degree Preparatory Program. The program involves prep classes at the Uniformed Services University, training to pass the MCAT – the med-school admissions test – and some exposure to actual clinical practice. It's important to keep in mind that entry is not guaranteed since admission to medical school is highly competitive.
Combat medic specialists are the people you see in movies that run into the battlefield to evacuate and treat the wounded. It's not an officer position, so you'll have to complete 10 weeks of basic training after you enlist. Then you go through 15 weeks of advanced training, learning the specialized skills in patient care techniques, emergency medical treatment and advanced medical care.
Just like other specialized military careers, becoming a medic requires you first pass the ASVAB, a military vocational test that measures whether you have the aptitude for this specialty.