This paper examines how selection into medicine in the United States influences physician practice styles. We exploit macroeconomic conditions at the time of medical school application as an exogenous shock to the applicant pool and show that labor market downturns in other prestigious fields increase applications to medical school, particularly among students with non-pre-medical backgrounds. This shift in applicant composition leads to cohorts of physicians who are more likely to work in lucrative, small group practices and to bill Medicare more per beneficiary, even after accounting for experience, specialty choice, and patient risk. Taken together, our findings highlight selection into medicine as a previously overlooked channel shaping physician practice styles and health care delivery.