Medicare Supplemental Insurance Reform Act of 1990

Medicare Supplemental Insurance Reform Act of 1990 - Amends title XVIII (Medicare) of the Social Security Act to prohibit a Medicare supplemental policy from being sold in any State if the policy's premium exceeds its premium for the previous year by a percentage greater than the projected percentage increase in Medicare costs, unless the premium increase has been approved by the State pursuant to a specified process providing for the detailed review of the reasonableness of such increase. Prohibits the sale of a Medicare supplemental policy which has neither been certified by the Secretary of Health and Human Services as meeting NAIC (National Association of Insurance Commissioners) Model Standards and returning a specified percentage of premiums as benefits, nor determined by a State regulatory program to be returning the requisite percentage of premiums as benefits. Increases the percentage of premiums which must be returned to policyholders as benefits. Requires that each State having a Medicare supplemental policy regulatory program maintain and make available to consumers a listing of the most recent year's ratio of benefits provided to, and premiums collected for, each policy sold in the State.