A bill to amend part B of title XVIII of the Social Security Act to limit to twenty percent the penalty for an individual's late enrollment under the supplementary medical insurance program for the aged and disabled.

Amends title XVIII (Medicare) of the Social Security Act to limit to 20 percent the monthly premium increase imposed for enrollment in the supplementary medical insurance program for the aged and disabled in the case of an individual who did not enroll in such program upon initially becoming eligible.