Professionals (doctors, lawyers) who come in to the service start as an O-3 (Captain) in the Air Force, once they've graduated OTS (Officer Training School) and completed all the required tests and certifications.

She could, theoretically, have left the service and then reentered later. In real life, it probably doesn't happen, but that's not to say it couldn't.

How long is OTS? Since she was born in 1965, it doesn't give us a lot of time to graduate HS, get a medical degree, get an advanced medical degree, and get experience enough to warrant this high-responsibility position. I'm hoping we can make a Janet career timeline. I'll research the medical front later this evening.

After graduating from high school, she would have needed to complete a bachelor's degree somewhere in some pre-med major. Medical school would be four years (two in class and two in rotation) and OTS is three months.

FYI, to give you my credentials, I'm former military and a lawyer, which has the same kind of entry rank and requirements (bachelor's degree, then professional school) as a doctor.

Thank you fanofall. That really helps.

So far, we have:
1965 - Born
1983 - Graduated HS at age 18 (assuming she was born at the beginning of the year)
1987 - Bachelors degree
1991 - Medical degree
???? - Officer Training School - She could have gone anytime after earning her Bachelors, but I'm assuming she would have waited until earning her MD. That way she would have come in as a Captain.
1997 - Assigned to the SGC as a Captain.
Her divorce would have taken place sometime before 1997 as well.

Also, I'm thinking that she would have gone beyond what a usual doctor would have done - in the same way that an ophthalmologist or psychiatrist has more than 4 years of medical schooling. She might have done another rotation in a specialty.

Of course, Janet might have been military before she went to medical school. In that case, my timeline is completely wrong. These gaps are what fanfiction is all about. (g)

This one I need to research. My gut instinct tells me you're right: the doctors drafted to work in Korea came in as Captains (instead of as Lieutenants) for precisely this reason: their MDs. But that was wartime, the draft, and the Army, of course.

Since we see Janet enter the SGC as a Captain, yet she's obviously somebody with enough mojo to be the CMO of a top sekrit MajCom facility, my guess is that she was Out and in civilian life and the USAF pulled her back in for the SGC. They'd have the option of doing so at the rank of her separation (like Jack, the eternal Colonel).

This would fit in with what little we have on her background from "Hathor" -- divorced and entered the Air Force after her divorce. We can presume therefore that the USAF may well have paid for medical school.

Yeah okay, rambling. I'll do some research on that Captaincy thing and get back to you...

That is EXACTly what I thought regarding her mojo. I have an idea (which you'll see appear in a story soon) and want to make sure that it fits in with reality as much as possible.

I know that in the past, they had a deal where - in exchange for paying part of medical school, you had to intern for a period of time. I know it existed for some medically-based careers in 1996, so I assume it applied to MDs as well.

Without giving away half of my story (g) a large percentage of doctors get divorced by the end of medical school because of the rigors of school. My guess is that may be what happened to her.

For those interested in military compensation for MD education, I found a very informative link. I'm not sure if I'm supposed to paste the link here, so ask and I will send it to you.