The medical expense deduction and income levels: Progressive or regressive?

The medical expense deduction (MED) allows taxpayers to deduct from taxable income a proportion of their out-of-pocket medical insurance and health care expenses. Because the rate of subsidy is equal to the marginal tax rate previous studies have found MED to be a regressive tax mechanism biased toward benefiting higher-income taxpayers. The authors demonstrate, using GINI coefficients, that MED makes the tax structure more progressive than it would otherwise be and increases equality of after-tax incomes.