Understanding the Medicare Enrollment Periods: A Guide for Professionals

Key Enrollment Periods for People With Medicare

Annual Medicare Advantage Open Enrollment Period

Jan.  1 – March 31

Who Is It For?

What Beneficiaries Can Do

When Does Coverage Start?

People already enrolled in a private Medicare Advantage (Part C) plan as of January 1 who wish to switch plans or leave their plan to get original Medicare (Parts A and B)

• Switch Medicare Advantage plans  

• Disenroll from Medicare Advantage to go to original Medicare (can also pick up a Part D drug plan)

First day of the month following the month of enrollment

(i.e., if they apply in January, coverage starts Feb. 1)

Annual Open Enrollment Period

Oct. 15 –Dec. 7

Anyone who is enrolled in Medicare Parts A and/or B, including those who may already be enrolled in a Medicare Advantage or Part D plan

• Change from original Medicare to a private Medicare Advantage plan  

• Change from Medicare Advantage to original Medicare  

• Join, drop, or switch Part D drug plans

• Switch Medicare Advantage plans

Jan. 1

Special Enrollment Period (SEP)

Ongoing (SEPs exist for people to enroll in Parts A and B, and to enroll in/switch Medicare Advantage and Part D plans)

There are numerous SEPs for both Medicare Parts A and B, Part D and Medicare Advantage plans. New Part A and B SEPs provide relief to people who miss a Medicare enrollment period due to an exceptional condition such as:

• Impacted by an emergency or disaster

• Health plan or employer error

• Formerly incarcerated people

• Coordinate with termination of Medicaid coverage

Part D and MA SEPs can apply to those who:

• Lose active employee/spousal coverage (and didn’t sign up for original Medicare when first eligible)

• Move out of a plan’s service area (for Medicare Advantage and Part D plans)

• Enter or leave an institution (nursing home, jail)

• Qualify for the Part D Low-Income Subsidy (Extra Help)

• Join Part A and Part B

• Change/enroll in a Part D plan

• Change/enroll in a Medicare Advantage plan

Note: Specific rules and timing apply to SEPs based on a person’s individual circumstances. Learn more from Medicare.

Varies; see Medicare link at left for more details

Medigap Open Enrollment Period (OEP)

Ongoing (6-month window after a person enrolls in Part B)

People turning 65, newly eligible for Medicare, and enrolled in Parts A and B

• Can purchase a Medigap policy without medical underwriting

Learn more in our fact sheet: Medigap Open Enrollment Period

First day of the following month

Key Enrollment Periods for People New to Medicare

General Enrollment Period

Jan. 1 – March 31

Who Is It For?

What Beneficiaries Can Do

When Does Coverage Start?

People who did not sign up for Medicare Parts A and/or B when first eligible and who do not have a Special Enrollment Period

• Sign up for Medicare Parts A and B

First day of the month following the month of enrollment

Initial Enrollment Period (IEP)

Ongoing (seven-month window around 65th birthday, or for those under 65 and found to have a disability, generally the month after a 24-month “waiting period”)

People newly eligible for Medicare, both those turning 65 and those under 65 who are found to have a disability by Social Security and have met their Medicare “waiting period” (i.e., received SSDI benefits for 2 years)

• Join Medicare Parts A and/or B, and also enroll in Part D

No earlier than month of Medicare eligibility; see Medicare & You handbook for more information

Medicare Advantage Open Enrollment Period within Initial Coverage Election Period (ICEP)

The month of entitlement to Parts A and B through the last day of the ICEP or third month of entitlement

People newly eligible for Medicare

• Can enroll in a Medicare Advantage plan, with or without drug coverage

First day of the month following the month of enrollment (and the person is enrolled in both Parts A and B)