7 Medicare Sign-Up Windows Retirees Should Know About — and the Ones You Can’t Miss

Many older adults do not realize they have several chances to enroll in Medicare or change their coverage.

For many Americans, reaching age 65 opens the door to Medicare enrollment. This federal health insurance program typically helps pay for most inpatient and outpatient care.

Retirees have more than one way to receive Medicare benefits, and they are not tied to a single plan for life. Instead, the government offers a range of enrollment periods that allow older adults to review their choices and make coverage changes.

Here’s a closer look at the main Medicare options and the enrollment windows available for signing up or switching plans.

The two primary Medicare options

People with Medicare generally choose between two main types of coverage:

• Original Medicare: This traditional version is provided directly by the government and has two parts. Part A covers hospital care, while Part B covers outpatient services. Most people pay the standard Part B premium, but not a Part A premium.
• Medicare Advantage: Also called Part C, these plans are offered by private insurers approved by the federal Medicare program. They must include everything covered by Original Medicare, and they may also offer extras such as vision or dental benefits. Premiums can vary.

Additional Medicare coverage options

Those who choose Original Medicare can also add one or both of the following:

• Part D: Original Medicare does not include prescription drug coverage, so retirees must choose a Part D plan for medications. These plans are sold by private insurers, and premiums vary. Medicare Advantage plans usually include drug coverage.
• Medigap: Also known as Medicare supplemental insurance, Medigap is sold by private insurers to help cover the “gaps” in Original Medicare. Medicare Advantage plans often include extra benefits that fill some of those gaps.

1. Initial enrollment period

When it is: This seven-month window includes the three months before the month you turn 65, the month you turn 65, and the three months after.

Who it applies to: People eligible for Medicare who are turning 65

What it is for: This is the first chance to enroll for people who do not yet have Medicare. During this period, you can:

• Choose Original Medicare or Medicare Advantage.
• Enroll in a prescription drug plan if you pick Original Medicare.

If you already receive Social Security benefits, you will generally be enrolled in Medicare automatically at age 65 and should receive information in the mail before your birthday. If you do not receive Social Security, you must apply for Medicare yourself.

2. Special enrollment period

When it is: This period lasts for eight months after you stop working or after employer health coverage ends.

Who it applies to: People with workplace health insurance, excluding COBRA coverage, who have not yet signed up for Medicare

What it is for: People covered by a group health plan through their own job or a spouse’s job do not have to enroll in Medicare at 65. They can wait until they leave employment or lose that coverage and then sign up during a special enrollment period.

People who already have a Medicare Advantage plan or a Medicare prescription drug plan may also qualify for a special enrollment period in certain cases, such as moving outside their plan’s service area.

Special enrollment periods may also be available for people affected by:

• Natural disasters or emergencies
• Incarceration
• Employer or health plan mistakes
• Loss of Medicaid coverage
• Other exceptional circumstances beyond your control

3. Medigap open enrollment period

When it is: This six-month window begins with the first month you have Medicare Part B and are age 65 or older.

Who it applies to: People who choose Original Medicare during initial enrollment

What it is for: This is the only period when the federal government guarantees access to a Medigap plan for people with Original Medicare, even if they have pre-existing conditions. If you miss it, an insurer may refuse to sell you a Medigap plan later, or you may face a higher premium.

Some states have additional Medigap enrollment opportunities for residents.

4. Open enrollment period

When it is: This period runs every year from Oct. 15 to Dec. 7.

Who it applies to: People who already have Medicare and want to change their coverage

What it is for: During open enrollment, all Medicare enrollees can make changes to their medical or drug coverage for the following year. Options include:

• Switching from Original Medicare to Medicare Advantage, or the other way around.
• Changing from one Medicare Advantage plan to another.
• Joining a drug plan, switching drug plans, or dropping drug coverage.

5. General enrollment period

When it is: This annual period runs from Jan. 1 to March 31.

Who it applies to: People who missed their initial enrollment period and do not qualify for a special enrollment period

What it is for: During this window, people can enroll in Medicare, and coverage starts on the first day of the month after they sign up.

Missing the initial enrollment period can also lead to a late-enrollment penalty, which may mean a higher premium for Part A, Part B, or both.

6. Medicare Advantage open enrollment period

When it is: This annual period also runs from Jan. 1 to March 31.

Who it applies to: People already enrolled in a Medicare Advantage plan

What it is for: Beneficiaries in Medicare Advantage can make one of the following changes during this period:

• Switch to another Medicare Advantage plan.
• Move from Medicare Advantage back to Original Medicare.
• Enroll in a Part D drug plan if they return to Original Medicare.

7. 5-star special enrollment period

When it is: This period runs annually from Dec. 8 to Nov. 30 of the following year.

Who it applies to: People already enrolled in a Medicare Advantage plan or a prescription drug plan

What it is for: Medicare assigns star ratings to Medicare Advantage and drug plans, and 5 stars is the highest rating. If a 5-star plan is available where you live, you may switch to it during the 5-star special enrollment period. You can only make one switch during this window.