To amend title XVIII of the Social Security Act to limit the penalty for late enrollment under the Medicare Program to 10 percent and twice the period of no enrollment, and for other purposes.

Amends part B (Supplementary Medical Insurance) of title XVIII (Medicare) of the Social Security Act to revise the late enrollment penalty to a 10% increase in the monthly part B premium due for premiums paid during a period equal to twice the number of months in each of the full periods of 12 months that the part B beneficiary could have been but was not enrolled under Medicare part B.

Excludes periods of COBRA and retiree coverage from calculation of the Medicare late enrollment penalty.

Establishes a special enrollment period for individuals whose COBRA or retiree coverage terminates.