The gender pay gap is wide in medicine but the extent of this disparity across specialties and over time have not been elucidated. Here we evaluate differences in Medicare reimbursement between men and women physicians over time and by specialty, controlling for physician and practice characteristics. The Centers for Medicare & Medicaid Services Payment Data was used to determine total reimbursements and number of services submitted by physicians practicing in the US between 2013 and 2019. Data from the American Community Survey (ACS) were used to determine average income, unemployment rates, poverty rates, income, and educational attainment levels by zip code for each physician's practice location. Among the 3,831,504 physicians included in this analysis from 2013-2019, 2,712,545 (70.8%) were men and 1,118,859 (29.2%) were women. Overall, men received more in Medicare reimbursements ($58,815 ± $104,772 vs. $32,205 ± $60,556, p<0.001) and billed more services (864 ± 1,780 vs. 505 ± 1,007, p<0.001) compared to women. The median Medicare reimbursement for men decreased from 2013 to 2019 from $59,710 to $57,874, while the median Medicare reimbursement for women increased from $30,575 to $33,456. Men were reimbursed more than women across all specialties with the greatest disparity in procedure-heavy specialties. The specialties with the highest difference in median Medicare reimbursement between men and women were ophthalmology ($99,452), dermatology ($84,844), cardiology ($64,112), nephrology ($62,352), and pulmonary medicine ($47,399). In linear regression models controlling for calendar year, years of experience, total number of services, and ACS zip-code-level variables, men received a higher amount of Medicare reimbursement in all specialties, as compared to women (p<0.01 for all). The percentage of top earning men (range: 65.0%-99.5%) surpassed the proportion of men in each specialty (range: 46.1%-94.6%), except public health and preventive medicine. Women physicians continue to receive lower total Medicare reimbursements than men physicians, particularly in procedure-heavy specialties. Lower clinical volume and fewer procedural services among women physicians partially contribute to the disparities in reimbursement.