People who collect Social Security or Railroad Retirement Board benefits will usually get Medicare Part A and Part B automatically. At that time, they are given the opportunity to enroll in a Medicare Advantage (Part C) and/or Part D plan. If someone is 65 and is not yet getting Social Security or Railroad Retirement Benefits, he will need to contact Social Security or the Railroad Retirement Board to sign up.

People who delay signing up for Part B when they are first eligible may have to pay a higher premium as a late enrollment penalty; especially if they were not covered under a group employer plan at the time of their initial eligibility. For those that qualify, the late enrollment penalty can be avoided by applying for the Medicare Savings Program.