The Physician Workforce: Distribution, Diversity, and Future Supply

The physician workforce in the United States is characterized by significant maldistribution, growing diversity despite persistent gaps, and projected supply challenges in certain specialties and geographic areas. Policy decisions about graduate medical education funding, specialty mix, geographic incentives, and immigration affect the future composition and distribution of the physician workforce in ways that have direct implications for patient access to care. Geographic maldistribution of physicians is severe. Physicians are highly concentrated in metropolitan areas, in affluent neighborhoods within those areas, and in states with larger urban populations. Rural counties across the United States are designated as health professional shortage areas, with physician-to-population ratios far below what is needed to meet primary care demand. The concentration of physicians in desirable urban and suburban locations reflects the combined effects of physician preferences, spousal employment considerations, training program locations, and financial incentives that have not been adequate to counteract these preferences. Specialty distribution is similarly unequal, though the dimensions of inequality differ from geographic maldistribution. Primary care specialties, including family medicine, general internal medicine, and general pediatrics, have lower average earnings than procedural specialties and attract smaller fractions of medical school graduates than population health needs would suggest is optimal. The specialty mix of new physicians has shifted away from primary care over recent decades despite persistent evidence that primary care-oriented health systems achieve better population health outcomes at lower cost. Graduate medical education, the period of residency and fellowship training after medical school, is primarily funded by Medicare, which pays hospitals for the costs of training residents. The number of Medicare-supported residency training positions, which determines how many physicians can train in the United States each year, has been effectively capped since 1997, despite significant growth in medical school graduation rates. The cap has created a bottleneck in physician production that affects the supply of all physician specialties. International medical graduates have historically filled a significant share of residency positions and have provided primary care and other specialty services in underserved areas at higher rates than US medical graduates. Visa and immigration policies that affect the ability of IMGs to train and practice in the United States have direct implications for physician supply, particularly in underserved areas that rely more heavily on this workforce. Uncertainty about immigration policy affects the decisions of international physicians considering training in the United States. Physician workforce diversity has increased over recent decades as medical school admissions have become more broadly representative of the US population, but significant gaps persist. Black and Hispanic physicians remain underrepresented relative to their population shares, and research documents that underrepresented minority physicians are more likely to practice in underserved communities and to serve patients from their own racial and ethnic groups. Increasing diversity in the physician workforce thus has both equity and access implications. Loan burden affects specialty choice among medical school graduates. The average medical school debt at graduation exceeds 200,000 dollars, and graduates who carry this burden face financial pressures that make lower-paying primary care specialties less attractive relative to higher-paying procedural specialties. Loan forgiveness programs targeted at physicians who practice in shortage areas or choose primary care specialties have been proposed and implemented in various forms, with mixed evidence on their effectiveness at changing career choices. Nurse practitioners and physician assistants have expanded their roles in providing primary care as the physician supply falls short of demand in certain areas and specialties. Research on quality of care provided by NPs and PAs in primary care finds outcomes comparable to physician care for routine primary care services. Scope of practice regulations, which vary across states, determine what services NPs and PAs can provide independently, and their expansion has been proposed as a strategy for addressing primary care access challenges in physician-shortage areas. The aging of the physician workforce adds urgency to supply concerns. A substantial share of practicing physicians are approaching retirement age, and the timing of retirements from the pandemic-stressed workforce may accelerate. Projections from the Association of American Medical Colleges consistently show significant projected shortfalls in physician supply relative to projected demand, with the largest gaps in primary care, psychiatry, and certain surgical specialties.