ImportanceGender inequities and limited representation are an obstacle to surgical workforce diversification. There has been limited examination of gender-based disparities in billing practices among surgeons.ObjectiveTo evaluate variations in practice metrics and billing practices among female and male surgeons and identify factors associated with gender disparities in Medicare reimbursements.Design, Setting, and ParticipantsThis retrospective cross-sectional study used publicly available Medicare Fee-for-Service Provider Utilization and Payment data from January to December 31, 2021, to identify demographics, annual services provided, and financial payments and charges for general surgeons, surgical oncologists, and colorectal surgeons. Data were analyzed from November 2023 to February 2024.ExposureThe primary exposure of interest was surgeon gender (ie, female or male).Main Outcomes and MeasuresThe annual total submitted charges and payments submitted in 2021 by female and male surgeons were assessed. Additionally, the total number and types of services provided each year and the number of beneficiaries treated were examined. Multivariable linear regression models were used to evaluate the association of surgeon gender with payments, number of services, and beneficiaries.ResultsA total of 20 549 general surgeons (5036 [24.5%] female; 15 513 [75.5%] male), 1065 surgical oncologists (450 [42.3%] female; 615 [57.7%] male), and 1601 colorectal surgeons (432 [27.0%] female; 1169 [73.0%] male) were included. Across all surgical subspecialties, female surgeons billed fewer mean (SE) Medicare charges (general surgeons: 30.1% difference; $224 934.80 [$3846.97] vs $321 868.50 [$3933.57]; surgical oncologists: 27.5% difference; $277 901.70 [$22 857.37] vs $382 882.90 [$19 566.06]; colorectal surgeons: 21.7% difference; $274 091.70 [$10 468.48] vs $350 146.10 [$8741.66]; all P < .001) and received significantly lower mean (SE) reimbursements (general surgeons: 29.0% difference; $51 787.61 [$917.91] vs $72 903.12 [$890.35]; surgical oncologists: 23.6% difference; $57 945.18 [$3853.28] vs $75 778.22 [$2622.75]; colorectal surgeons: 24.5% difference; $63 117.01 [$2248.10] vs $83 598.53 [$1934.77]; all P < .001). On multivariable analysis, a reimbursement gap remained across all 3 surgical subspecialties (general surgeons: –$14 963.46 [95% CI, –$18 822.27 to –$11 104.64] [P < .001]; surgical oncologists: –$8354.69 [95% CI, –$15 018.12 to –$1691.25] [P = .01]; colorectal surgeons: –$4346.73 [95% CI, –$7660.15 to –$1033.32] [P = .01]).Conclusions and RelevanceIn this cross-sectional study, there was considerable gender-based variation in practice patterns and reimbursement among different surgical subspecialties serving the Medicare population. Differences in mean payment per service were associated with variations in billing and coding strategies among female and male surgeons.