H.R.2591 - Federal Government - To amend part B of title XVIII of the Social Security Act to limit the penalty for late enrollment under part B of the Medicare Program to 10 percent and twice the period of no enrollment, and to exclude periods of COBRA and retiree coverage from such late enrollment penalty.

Amends part B (Supplementary Medical Insurance) of title XVIII (Medicare) of the Social Security Act to: (1) limit the penalty for late enrollment under part B to 10% and twice the period of no enrollment; and (2) exclude periods of COBRA and retiree coverage from such late enrollment penalty.

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