BackgroundThe purpose of this study was to evaluate changes in regional and national variations in reimbursement to arthroplasty surgeons, procedural volumes, and patient populations for total hip arthroplasty (THA) from 2013 to 2021. MethodsThe Medicare Physician and Other Practitioners database was queried for all billing episodes of primary THA for each year between 2013 and 2021. Inflation-adjusted surgeon reimbursement, procedural volume, physician address, and patient characteristics were extracted for each year. Data were stratified geographically based on the United States Census regions and rural–urban commuting codes. Kruskal–Wallis and multivariable regressions were utilized. ResultsBetween 2013 and 2021, the overall THA volume and THAs per surgeon increased at the highest rate in the West (+48.2%, +20.2%). A decline in surgeon reimbursement was seen in all regions, most notably in the Midwest (−20.3%). Between 2013 and 2021, the average number of Medicare beneficiaries per surgeon declined by 12.6%, while the average number of services performed per beneficiary increased by 18.2%. In 2021, average surgeon reimbursement was the highest in the Northeast ($1,081.15) and the lowest in the Midwest ($988.03) (P < .001). Metropolitan and rural areas had greater reimbursement than micropolitan and small towns (P < .001). Patient age, race, sex, Medicaid eligibility, and comorbidity profiles differ between regions. Increased patient comorbidities, when controlling for patient characteristics, were associated with lower reimbursement in the Northeast and West (P < .01). ConclusionsTotal hip arthroplasty (THA) volume and reimbursement differ between US regions, with the Midwest exhibiting the lowest increase in volume and greatest decline in reimbursement throughout the study period. Alternatively, the West had the greatest increase in THAs per surgeon. Patient comorbidity profiles differ between regions, and increased patient comorbidity is associated with decreased reimbursement in the Northeast and the West. This information is important for surgeons and policymakers as payment models regarding reimbursement for arthroplasty continue to evolve.