Advanced Practice Providers Assistant-at-Surgery Services Across Surgical Specialties in Medicare: 2017-2024

BACKGROUND: Advanced practice providers (APPs), including nurse practitioners and physician assistants (PAs), increasingly participate in surgical care, but the national extent and evolution of their role as surgical first assistants remain poorly characterized. We evaluated longitudinal trends and specialty-level variation in APP assistant-at-surgery use. STUDY DESIGN: We conducted a repeated cross-sectional analysis of CMS Physician/Supplier Procedure Summary 100% Medicare Part B files from 2017 through 2024. We examined the 10 highest-volume operations in each of 14 surgical subspecialty groups with 90-day global periods and unrestricted assistant-at-surgery eligibility (140 procedures). The outcome was APP assistant-at-surgery services per 1,000 index operations. RESULTS: In 2024, APPs billed 784,066 assistant-at-surgery services across 2,094,083 eligible operations (37.4%), compared with 30.2% in 2017 (mean annual change, 1.01 percentage points; 95% CI, 0.95-1.07). PAs accounted for 86% of APP assistant services in 2024. APP utilization increased across all 14 surgical specialties but varied substantially, from 1.8% in ophthalmology to 57.5% in orthopedic surgery. APP assistance was reported for 65.1% of total knee arthroplasties. Plastic surgery demonstrated 105% relative growth, with utilization differences across specialties narrowing over time. CONCLUSIONS: APPs now account for more than one-third of assistant-at-surgery services relative to eligible major operations in Medicare, with increasing utilization across all examined surgical specialties. These national trends establish the growing contribution of APPs to operative staffing and provide evidence to inform surgical workforce planning.