Scenarios, not shortage forecasts, are key to better workforce policy.

Current and projected shortages in the US health workforce have prompted policymakers to propose reforms to Medicare Graduate Medical Education (GME) and nursing programs. However, researchers have historically faced challenges in accurately predicting workforce trends; physician and nurse supply and demand all grew faster than expected over the past 2 decades. These discrepancies highlight the need for scenario-based workforce planning and projection models that estimate how a policy intervention would affect the workforce outcome of interest. In addition, policy options modeled should address not only increasing provider-to-population ratios but also improving health outcomes through innovative payment and care models.