Enrollment Periods

Medicare Part B Enrollment Periods

Initial Enrollment Period

The initial enrollment period based on age begins three months before the month you become age 65 and ends three months after the month you become age 65, if you meet all other requirements.

Important: If your birthday is on the first day of the month, you actually reach age 65 the month before your birth month.

Example: If you were born on 2/1/1943, your initial enrollment period is Oct 08, Nov 08, Dec 08, Jan 09, Feb 09, Mar 09 and Apr 09.  If you were born on 2/2/1943, your intial enrollment period is Nov 08, Dec 08, Jan 09, Feb 09, Mar 09, April 09 and May 09.  If you are not aware of this rule and miss your enrollment period, Social can make an exception.

There are other rules for those receiving disability or have chronic renal disease.

The date the coverage begins will vary based on the date you enroll.4


Example: If you become age 65 in July, your initial enrollment period begins the month of April and ends the month of October.

  • If you enroll for Medicare Part B in April, May or June, your coverage will begin in July.
  • If you enroll in July, your coverage will begin August 1st
  • If you enroll in August, your coverage will begin October 1st
  • If you enroll in September, your coverage will begin December 1st
  • If you enroll in October, your coverage will begin January 1st

General Enrollment Period

The general enrollment period is January through March of each year. When you enroll for Part B in the general enrollment period, your coverage always begins July 1st of the year you enroll.

There is a premium surcharge of 10% for each full twelve-month period you are not enrolled for Medicare Part B and were first eligible. Social Security does not count months you were covered under a group health plan when figuring the surcharge.

There is no time limit for requesting premium surcharge rollback. An individual who is already entitled to Part B or who is filing a general enrollment request may request relief from the premium surcharge at any time.

Special Enrollment Period

Individuals who are age 65 and over or disabled, can enroll (or reenroll) in Medicare Part B and/or Premium Hospital Insurance:

  • During any month you are enrolled in an employer group health plan (20 employees or more) based on your current work  or the current work of your spouse or
  • During any of the eight consecutive months after you or your spouse’s employer group health plan terminates or you or your spouse’s work ends, whichever comes first.

Cobra does not count as employer group health plan coverage. You must always file for Medicare Part B if you go on a Cobra Plan.

NOTE: The requirements for coverage under an employer group health plan based on 20 or more employees do not apply to “disabled family members.”


Note: You cannot have a special enrollment period if you are in your initial enrollment period. (Three months before your 65th birthday and 3 months after your 65th birthday.) If your birthday falls on the first day of month, you reach age 65 in the month before your birthday.