Important Dates

AEP, OEP, SEP, Effective Dates

January 1

New coverage begins if you made a change. If you kept your existing coverage and your plan’s costs or benefits changed, those changes will also start on this date.

January 1 to March 31
General Enrollment Period

If you didn’t sign up for Part A (if you have to buy it) and/or Part B (for which you must pay premiums) during your Initial Enrollment Period, and you don’t qualify for a Special Enrollment Period, you can sign up between January 1–March 31 each year. Your coverage won’t start until July 1 of that year, and you may have to pay a higher Part A and/or Part B premium for late enrollment. If you enroll in Parts A and B during this period, you have three months (April through June) to enroll in a Part D plan or to enroll in a Medicare Advantage plan. Enrolling in Medigap plans depends on state laws.

January 1 to March 31
Medicare Advantage Open Enrollment Period (OEP)

MA plan enrollees may enroll in another MA plan or disenroll from their MA plan and return to Original Medicare. Individuals may make only one election during period. If you’re in a Medicare Advantage Plan, you can make a change to a different Medicare Advantage Plan or switch back to Original Medicare (and join a stand-alone Medicare Prescription Drug Plan) once during this time. Any changes you make will be effective the first of the month after the plan gets your request.

October 15 to December 7
Medicare Annual Enrollment Period (AEP)

During this period Beneficiaries may switch, enroll, or disenroll in available MA plans, Medigap policies, or Part D Prescription Drug Plans. New plans will be effective January 1 of the following year. Guidelines apply. Change your Medicare health or prescription drug coverage for the following year, if you decide to. This includes returning to Original Medicare or joining a Medicare Advantage Plan.

Initial Enrollment Period (IEP/ICEP)

This is the time frame most people sign up for Medicare. A seven-month period, starting three months before the month in which you turn 65 and ending three months after that month (assumes you do not delay in Part B benefits).

Special Election Periods (SEP) – Non-Dual Eligibles

Special enrollment periods may apply for change of residence, loss of group coverage, or if your plan withdraws from the market for the upcoming year.

Special Election Periods (SEP) – Dual Eligibles and Extra Help

Special enrollment period for Dual Eligibles and those receiving Extra Help, is where you can join, switch, or drop your Medicare Advantage plan or Medicare Prescription Drug coverage. There is a one time change allowed during each of these periods:

  • January – March
  • April – June
  • July – September

If you do make a change, it will go into effect on the first day of the following month. You will need to wait until the next period to make another change. To make a change in the last quarter of the year, you must use the Medicare Annual Enrollment Period (AEP) October 15 – December 7.

September 30 – ANOC letter

Private plans are required to send you an Annual Notice of Change (ANOC) letter that includes any changes in coverage, costs, service area, and more that will be effective starting in January, by September 30.

October 1 – New Part D Policy Details

Insurers begin publishing premium prices and coverage details of offered Medicare Part D prescription drug plans each year on October 1.

October 15 – EOC Letter

This Evidence of Coverage (EOC) notice gives you details about what your plan covers, how much you pay, and more. Your plan will send you a notice (or printed copy) by October 15.