The big medical centers, like Walter Reed, always did free plastic surgery for "practice" for the service members stationed at those bases. The military has plastic surgeons to do reconstructions after cancer, accidents and what have you and they have to learn somewhere so they practice on the troops. I'm pretty sure you could even travel to those bases on your own leave time with command approval prior to the media saying anything about it. They're just out of shit to write about.
That said, I served a little over 6 years and I got my boobs done while active duty, on my own leave time...and knowing what I know about military doctors I opted to pay a civilian surgeon for the work. Sometimes you get what you pay for and free boobs from a newbie plastic surgeon....eichhhh......