Payment adjustments by physician specialty and participation type in the Merit-Based Incentive Payment System.

BACKGROUND: The Merit-Based Incentive Payment System (MIPS) is a federal program that adjusts Medicare physician payment based on performance across four domains: quality measures, cost, improvement activities, and promoting interoperability. Clinicians primarily participate either through a group or through a MIPS alternative payment model (APM), in which performance is aggregated at the health system level. Although APM participation is generally associated with higher scores than group reporting, the specialty-specific financial implications of this difference have not been quantified. METHODS: Using coarsened exact matching and weighted quantile regression on 2023 Centers for Medicare and Medicaid Services data from 291,121 clinicians across 29 specialties, we compared participation rates and estimated median payment adjustments under each reporting structure. RESULTS: APM participation varied substantially by specialty, ranging from 7.6% in dermatology to 40.6% in hospital medicine. We found that across nearly all specialties, clinicians participating through an APM received meaningfully higher predicted payment adjustments than otherwise comparable group-reporting clinicians. The adjusted difference ranged from $100 for obstetrics/gynecology to $2327 for radiation oncology. DISCUSSION: These findings suggest that MIPS reimbursement reflects not only clinical performance but also the structural pathway through which that performance is reported. Specialist physicians, who tend to have lower APM access, may face a systematic financial disadvantage. Given that MIPS participation itself carries estimated costs of several thousand dollars per physician annually, specialties with limited APM access may experience a net financial burden. Expanding specialty-relevant APM measure sets and improving APM access could help align incentives more equitably across disciplines.