Association for Public Policy Analysis & Management

Objective: Over the past decade, U.S. medical school enrollment has increased nearly 30 percent and growth in mid-level new graduates was even faster. It is reported that the number of medical school graduates increased by about 8% during 2012 and 2015. It is likely that many of these new graduates are currently serving the large and growing Medicare population. Yet, little evidence so far has documented the workforce that are serving Medicare population. In the anticipation of physician supply shortages, it is important to understand who are taking care of Medicare population recently, and whether there are changes in the overall capacity and patient risk profiles of Medicare providers.

Study Population: All U.S. physicians and nurses with more than 10 Medicare Part B beneficiaries between 2012 and 2015.

Data: We obtained publicly available data (2012-2015) from Medicare Physician and Other Supplier Aggregate Tables published by U.S. Centers for Medicare & Medicaid Services. The data contain information on utilization, payment, and procedures provided to Medicare Part B fee-for-services beneficiaries by U.S. physicians and nurses.

Methods: We identified primary care physicians (i.e., family practice, internal medicine, general practitioners, and geriatric medicine), specialists, and mid-level providers (e.g., nurse practitioners, physician assistants, etc.) based on self-reported provider type. We conducted trend analysis to examine the changes in the share of physicians and mid-level providers, and compared utilization, payment, and patient risk profiles of these providers between 2012 and 2015, and by physicians and nurses.

Findings: Over the study period, the number of providers with more than 10 Medicare patients increased from 709,982 in 2012 to 782,836 in 2015. Among these providers, the share of physicians declined consistently, and specifically, both the shares of primary care physicians and specialists declined. While in contrast, the share of mid-level providers (including nurse practitioners and physician assistants) increased correspondingly, from 20% in 2012 to 24% in 2015. Compared to 2012, in 2015, on average providers had 20 fewer unique Medicare beneficiaries, but had 0.4 more services provided to per beneficiary, and received less payment amount. Physicians on average in 2012 had fewer Medicare patients, more services provided to per patient, and no changes in payment received than in 2015, while nurses had more patients, provided more services per patient, and received higher payments in 2015 than in 2012. Both physicians and nurses had more patients with depression, asthma, chronic kidney disease, and stroke from 2012 to 2015.

Conclusion and Policy Implications: Medicare provider composition has been changing in recent years, where mid-level providers are playing an increasing role in serving Medicare beneficiaries. State legislatures and policymakers may consider expanding scope-of-practice for mid-level providers. They may also need to weigh the importance of innovating new payment policy to better reimburse mid-level providers. Yet, our analysis was unable to capture those newly registered providers and providers with fewer than 10 patients. Future research is warranted to compare the capacity of new and existing providers and the relationship between year of practicing and capacity building to serve more Medicare patients.