The starting pay should be no different than for a man.
However, physician pay is usually negotiated. Women often don't negotiate as aggressively as men and they are more likely than men to "leave money on the table." The employer may have offered $180k. The physician will realize that this is a lowball offer. A woman is more likely to ask for $190k, out of concern for asking for too much. The employer wanted to pay $200k, so they accept $190 and are delighted at saving $10k! Men are more likely to feel confident returning a counter offer of $240k. They know they probably won't get that, but they are less likely to be afraid of alienating the employer with too high a bid. The employer isn't happy about having to go above $200k, but they stretch up to $210k. There is still some space between that figure and the $240k he asked for, so he can come back with a $225k offer and he just might get it. Even if the company stands firm at $210k, that is $20,000 more than the female physician gets.
When changing jobs, employers frequently consider prior compensation to give them a sense of what the candidate for a position will be willing to accept. Leaving money on the table early in one's career can mean lower income for many years to come, which can add to millions over a 30-40 year career.
These are trends, and they don't account for all of the pay disparity. But it certainly is part of the equation. Women in the US are socialized to be more sensitive to the way others feel than men are. Women often receive messages that they are responsible for the happiness of others. In the work place, being agreeable and cooperative can be beneficial traits, but when it comes to salary negotiation one needs confidence, assertiveness, and even a little selfishness. Women can have those traits, just as some men can be too accomodating, but on trend, it goes the other way.
The other issue is that there isn't one typical FM pay scale. It varies widely by region and nature of the practice. There are doctors who may be working for considerably less than $200k on a full time schedule if they are in a desirable location where it isn't hard to fill positions. In areas where jobs are harder to fill or for physicians who are willing to do travel gigs / locums work, the pay can even exceed $300k. None of that has to do with gender, but rather what the physician thinks to ask for and what conditions they are willing to accept.
