Breaking Down the Medicare Enrollment Calendar Month by Month

Learn when you can sign up and change Medicare plans

Medicare Enrollment Periods
Enroll in Medicare before time runs out. Utamaru Kido/Moment Open/Getty Images

Enrolling in Medicare or changing Medicare plans is not hard but knowing when you can do it can be confusing. There are a number of Medicare enrollment periods throughout the year but only a few that may apply to your situation. This calendar will help you to keep them straight.

Initial Enrollment Periods:

First and foremost, you have to understand your Initial Enrollment Period (IEP). This is when you first apply for Medicare.

Your IEP dates will vary based on your personal circumstances. Missing your IEP could result in your having to pay late penalties.

  • Based on age: You are eligible for Medicare when you turn 65 years old. Your IEP begins three months before and ends three months after your 65th birthday.
  • Based on employer-sponsored health coverage: If you are 65 years old and have health coverage through an employer who hires at least 20 full-time employees, your IEP begins the day you leave your job or the day you lose that health coverage, whichever comes first, and lasts for eight months.
  • Based on end-stage renal disease: Your IEP begins the month you are diagnosed and lasts for an additional three months.
  • Based on disability with SSDI: You are eligible for Medicare after receiving SSDI benefits for 24 months. The Social Security Administration will automatically enroll you in Medicare on the 25th month.

    General Enrollment Period:

    January 1 - March 31

    If you missed your Initial Enrollment Period, this is when you can sign up for Part A, Part B or both. You cannot select a Medicare Advantage plan at this time. Your Medicare benefits will not begin until July 1.

    Medicare Advantage Disenrollment Period:

    January 1 - February 14

    If you decide you do not like your Medicare Advantage plan, you can drop it and change over to Original Medicare during this disenrollment period. You can also pick a Part D plan to supplement your Original Medicare coverage at this time. What you cannot do is change from one Medicare Advantage plan to another or change from one Part D plan to another.

    Special Enrollment Period:

    April 1 - June 30

    If you signed up for Medicare during the General Enrollment Period, this is when you can sign up for a Part D plan. You may also enroll in a Medicare Advantage plan with Part D coverage, an MA-PD plan. You cannot pick a Medicare Advantage plan without prescription drug coverage at this time. Your benefits will begin July 1.

    Open Enrollment Period:

    October 15 - December 7

    This enrollment period is available to everyone on Medicare. During this time you can change from Original Medicare with or without a Part D plan to a Medicare Advantage with or without prescription drug coverage and vice versa. You can also sign up for, cancel or change Part D plans.

    Five Star Enrollment Period:

    December 8 - November 30

    If you want to sign up for a Five-Star Medicare Advantage plan or a Part D plan, you can do so from December 8 after the plan earns its Five-Star rating to November 30 of the following year.

    You have the option of doing this only once a year. If you want to leave the Five-Star plan for any reason, you will have to wait until the Open Enrollment Period to do so.