When Medicaid Pays the Bill: Routine Vision Benefits, Eye Care Use, and Eyeglasses Spending Among Dual-eligible Medicare Enrollees -- by Michel H. Boudreaux, Brandy Lipton, Melissa McInerney

Vision problems are prevalent among Medicare beneficiaries, with the majority having treatable conditions including uncorrected refractive error and cataracts. However, traditional Medicare does not cover routine eye exams or eyeglasses, and Medicare Advantage supplemental vision benefits often include low annual limits. We examine the effects of Medicaid routine vision benefits among adults dually eligible for Medicare and Medicaid, a population with high rates of vision impairment, morbidity, and disability. Using 2002-2019 Medicare Current Beneficiary Survey data and a difference-in-differences design, we estimate that Medicaid routine vision benefits increase past-year eye exams, eyeglasses purchases, and Medicaid spending on eyeglasses while reducing out-of-pocket spending. We also find suggestive evidence of spillovers to Medicare Advantage spending on eyeglasses, consistent with Medicaid routine vision coverage inducing additional eyeglasses purchases among Medicare Advantage enrollees with supplemental vision benefits, although estimates are modest.