Medicare Part B (Medical Insurance)

Individuals already receiving Social Security or RRB benefits at least 4 months before being eligible for Medicare and residing in the United States (except residents of Puerto Rico) are automatically enrolled in both premium-free Part A and Part B. People who are automatically enrolled have the choice of whether they want to keep or refuse Part B coverage. People living in Puerto Rico who are eligible for automatic enrollment are only enrolled in premium-free Part A; they must actively enroll in Part B to get this coverage.

Individuals who are not receiving a Social Security or RRB benefit are not automatically enrolled. Individuals who previously refused Part B, or who terminated their Part B enrollment, may enroll (or re-enroll) in Part B only during certain enrollment periods. In most cases, if someone does not enroll in Part B when first eligible, they will have to pay a late enrollment penalty for as long as they have Part B.

Part B is a voluntary program that requires the payment of a monthly premium for all parts of coverage. Eligibility rules for Part B depend on whether a person is eligible for premium-free Part A or whether the individual has to pay a premium for Part A coverage.

Individuals who are eligible for premium-free Part A are also eligible for enroll in Part B once they are entitled to Part A.

Individuals who must pay a premium for Part A must meet the following requirements to enroll in Part B:

Be age 65 or older;

Be a U.S. resident; AND

Be either a U.S. citizen, OR

Be an alien who has been lawfully admitted for permanent residence and has been residing in the United States for 5 continuous years prior to the month of filing an application for Medicare.

NOTE : Individuals who were terminated from Part A 36 months after receiving a kidney transplant may be eligible for the Part B Immunosuppressive Drug benefit. Learn more about Part B Immunosuppressive Drug Coverage .