Medicare Reimbursement Act of 1991 - Amends the Internal Revenue Code to impose an additional occupational tax on manufacturers and importers of cigarettes equal to the amount of smoking-related medical costs multiplied by the percentage of cigarettes sold during the preceding year in the United States.

Sets forth the smoking-related medical costs for the three-year period beginning after December 31, 1991. Declares the costs for the three-year period beginning after December 31, 1994, to be the amount determined to be equal to the average annual amount estimated to have been expended for the care and treatment of smoking-related cancers, circulatory system diseases, and respiratory diseases under title XVIII of the Social Security Act (Medicare).

Appropriates increased cigarette tax revenues to the Federal Hospital Insurance Trust Fund and the Federal Supplementary Medical Insurance Trust Fund under the Medicare program for smoking-related medical costs.