Health insurance coverage among incident cancer cases from population-based cancer registries in 49 US states, 2010-2019.

Having health insurance coverage is a strong determinant of cancer care access and survival in the United States. The expansion of Medicaid income eligibility under the Affordable Care Act has increased insurance coverage for working-age adults. Using data from the Cancer Incidence in North America (CiNA) in 2010-2019, we identified 6 432 117 incident cancer cases with known insurance status diagnosed at age 18-64 years from population-based registries of 49 states. Considerable variation in Medicaid coverage and uninsured rate exists across states, especially by Medicaid expansion status. Among expansion states, Medicaid coverage increased from 14.1% in 2010 to 19.9% in 2019, while the Medicaid coverage rate remained lower (range = 11.7% - 12.7%) in non-expansion states. The uninsured rate decreased from 4.9% to 2.1% in expansion states, while in non-expansion states, the uninsured rate decreased slightly from 9.5% to 8.1%. In 2019, 111 393 cancer cases (16.9%) had Medicaid coverage at diagnosis (range = 7.6%-37.9% across states), and 48 357 (4.4%) were uninsured (range = 0.5%-13.2%). These estimates suggest that many patients with cancer may face challenges with care access and continuity, especially following the unwinding of COVID-19 pandemic protections for Medicaid coverage. State cancer prevention and control efforts are needed to mitigate cancer care disparities among vulnerable populations.