Enrolling in Medicare Programs

Enrolling in Medicare Part A or B

Medicare has four parts: Part A, called hospital insurance; Part B, medical insurance; Part C, Medicare Advantage managed care plans; and Part D, prescription drug plans. Most people are eligible for any of these Medicare programs at age 65.

Some people may want to sign up for only one part of Medicare or for several. But each part has a different enrollment procedure, and the processes differ depending on whether she's already receiving Social Security or other federal pension benefits or is a member of a managed care plan and wants to continue. When and how to enroll can get confusing, so the procedures and timing for each situation and Medicare program are described below.

Automatic enrollment in Medicare Part A if the person is already receiving Social Security or other federal pension benefits

If the person is approaching age 65 and is already receiving Social Security, Railroad Retirement, or federal civil service pension benefits -- retirement, disability, or dependents' or survivors' benefits -- she doesn't need to do anything to enroll in Medicare Part A. The Social Security Administration will do it for her. About three months before her 65th birthday, she'll receive an initial enrollment period package in the mail. Included will be notification of her enrollment in Medicare Part A. Because she is eligible for Social Security or other federal pension benefits, she's also eligible for free Part A coverage. That means she won't have to pay any monthly premium for Part A. Her coverage will begin on her 65th birthday. If she doesn't receive these documents by two months before she turns 65, she should contact the Social Security Administration at 800-772-1213.

If she's under age 65 but has been eligible to receive Social Security disability benefits for at least 24 months, she's also eligible for free Medicare Part A and will be automatically enrolled. The Social Security Administration will mail Medicare enrollment documents to her when she reaches her 24th month of collecting disability benefits.

How and when to enroll in Medicare Part A if someone isn't receiving Social Security or other federal pension benefits

If the person isn't collecting Social Security or other federal pension retirement, disability, or dependents' or survivors' benefits, she has to apply for Medicare Part A at a local Social Security office. She should file her application as early as three months before she turns 65, to ensure that the paperwork is completed by her 65th birthday.

If she's eligible for Social Security or other federal pension benefits but hasn't yet started collecting them, she will receive free Part A coverage, with no monthly premium. If she is 65 and a citizen or legal resident but doesn't qualify for Social Security or other federal pension benefits, she can still apply for Medicare Part A. However, she will have to pay a monthly premium for it; the amount is determined by how many Social Security work credits she has accumulated.

If she applies for Medicare Part A within six months after she turns 65, her coverage will date back to her 65th birthday. If she applies more than six months after her birthday, her coverage will date back only to six months before the date she applied.