Upon turning 65, U.S. cancer patients experience the “Medicare Effect’ of better outcomes relative to patients nearly 65. Context likely mediates this effect, but so might differential access to care. With population-based cancer registry data, we construct a Difference-in-Discontinuities framework test if this “Medicare Effect” on cancer detection and survival varies in counties with and without a Critical Access Hospital (CAH), before and after CAH conversion. Consistent with prior literature, gaining Medicare was associated with reduced probability of distant stage diagnosis and improved two-year survival. Exposure to CAHs did not change Medicare’s effect on detection, but did increase Medicare’s effect on all-cause survival for males with prostate cancer (Est. = +0.019, se = 0.005), and females with lung (+0.046, se = 0.021) and colorectal cancer (Est. = +0.076, se = 0.026). Policies improving cancer survival remain warranted for both men and women with, and without Medicare.

The authors have declared no competing interest.

This study did not receive any funding.

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