Medicare Eligibility Expansion Act of 1991 - Amends title II (Old Age, Survivors and Disability Insurance) (OASDI)of the Social Security Act (the Act) to waive the 24-month waiting period required to receive benefits under part A (Hospital Insurance) of title XVIII (Medicare) of the Act for individuals who are 62 years of age or older and are entitled to social security disability benefits.

Amends the Hospital Insurance program to allow early retirees receiving OASDI benefits and the spouses who are 62 years of age or older and children of such retirees to purchase Medicare coverage including coverage under part B (Supplementary Medical Insurance) of the Act. Establishes applicable monthly part A premiums for calendar years 1992 through 1996, with premiums thereafter to be determined by the Secretary of Health and Human Services and indexed to the increase in the part A deductible.