We examine how the amount a physician is paid influences who they are willing to see. To do so, we exploit large, exogenous changes in Medicaid reimbursement rates driven primarily by a federal mandate—which required that states raise Medicaid payments to match Medicare rates for primary care visits—to quantify the impact of physician payment on access to treatment and health. We find that increasing Medicaid payments to primary care doctors is associated with improvements in access, better self-reported health, and fewer school days missed among beneficiaries. We find no evidence of negative spillovers to the privately insured.