​Summary: During the period 2014–16 the Affordable Care Act (ACA) dramatically reduced rates of uninsurance and underinsurance in the United States. In this study, authors estimated the effects of these coverage increases on cancer detection among the near-elderly population (ages 60–64). 

Findings: Using 2010–16 Surveillance, Epidemiology, and End Results (SEER) Program data, authors estimated that the ACA increased cancer detection among this population. Authors found that 45% of the jump in cancer detection that occurs when people reach Medicare eligibility age was eliminated by the ACA coverage expansions. The ACA coverage expansions had large effects on cancers with and without routine screening tests, and 68% of newly detected cancers were early- and middle-stage cancers. In addition, the empirical strategy used to identify the effects of the ACA on cancer detection confirmed the role of health insurance as the key mechanism to explain Medicare’s effects on health care use and health outcomes as described in the prior literature. Authors' results highlight the importance of the ACA, Medicare, and health insurance coverage generally for disease detection.​