After internship, the vast majority of American doctors go directly into their chosen residency for further specialty training.
I did not.
My Navy contract states that I will provide seven years of service in exchange for my education and some of that is usually applied to the time after internship. I chose to attend flight school to learn to be a flight surgeon. The name is a little misleading and should be more like: primary care and occupational health for pilots and aircrew. Flight surgeon sounds better to me.
So after internship, I spent 6 months completing this training and then 2 years with the Marine Corps. I was the primary care doctor for my squadron while we were preparing to deploy and then while deployed on ship. It was a large deck amphibious carrier, a couple hundred feet shorter than an aircraft carrier but still very large. We had over 20 aircraft on our deck and many hovercrafts in our well deck. There were thousands of sailors and marines on my ship and 507 of them were mine to care for.
As the only flight surgeon, I had the opportunity to execute medevacs when sailors or marines were injured and outside the capabilities of our ship’s medical capability. My ship and my squadron thankfully never participated in hostility however the nature of the job is dangerous and we had injuries to treat, just like any other dangerous profession. On a ship. Many times in the middle of nowhere.
During my deployment, I applied for radiology residency and a few months after I returned home from the Persian Gulf I was a resident at the Naval Medical Center in San Diego.