Physician workforce projections often include scenarios that forecast physician shortages under different assumptions about the deployment of physician assistants (PAs) and nurse practitioners (NPs). These scenarios generally assume that PAs and NPs are an interchangeable resource and that their specialty distributions do not change over time. This study investigated changes in PA and NP specialty distribution in North Carolina between 1997 and 2013. The data show that over the study period, PAs and NPs practiced in a wide range of specialties, but each profession had a specifi c pattern. The proportion of PAs-but not NPs-reporting practice in primary care dropped signifi cantly. PAs were more likely than NPs to report practice in urgent care, emergency medicine, and surgical subspecialties. Physician workforce models need to account for the different and changing specialization trends of NPs and PAs
