Missed Medicare Open Enrollment? Here’s What to Do Next

Your new coverage would begin the first day of the month after you change. However, you can’t switch from original Medicare to a Medicare Advantage plan during Medicare Advantage open enrollment.

The Medicare Advantage open enrollment period does not apply to stand-alone Part D plans. You can’t join a Part D prescription plan in this period if you have original Medicare or want to switch to another stand-alone plan.

And if you don’t already have a Medicare Advantage plan, you can’t get one during this time — unless this time happens to coincide with another type of enrollment period.

Be aware: If you leave Medicare Advantage for original Medicare and want a Medigap policy to help cover Medicare’s deductibles and copayments, this supplemental coverage may not be guaranteed. Medigap insurers in most states can charge more or reject you because of preexisting conditions unless you buy a Medigap policy during certain times.

Other circumstances could make you eligible to switch to a Medicare Advantage plan midyear.

• Moving outside your current plan’s service area. When you relocate, you usually have two months to get a new Medicare Advantage plan or leave Medicare Advantage for original Medicare and get a Part D plan. This will also allow you to buy a Medigap policy regardless of preexisting conditions.
• Qualifying for a special enrollment period. For example, you can switch plans if you move into or out of a long-term care facility or if you qualify to join a chronic condition special needs plan.
• Finding a five-star plan in your area. If a locally available Medicare Advantage plan has an overall five-star quality rating from the government, you can switch to that plan one time outside of open enrollment. But this is rare: Only 18 plans across the country — less than 1 percent — qualify for 2026. You can search for plans with a five-star rating using the Medicare Plan Finder.

Coverage begins the first day of the month after a plan receives your enrollment request.

When can I switch Part D plans after open enrollment?

If you discover another Part D plan has better coverage for your medications, or if your doctor prescribes a new drug that isn’t covered in your plan’s formulary, you may have opportunities to change plans after Dec. 7. These special circumstances apply if you:

• Move out of your plan’s service area. You usually have up to two months to change to another plan.
• Qualify for a special enrollment period. For example, if your Part D plan terminates its contract with Medicare.
• Receive financial assistance from the Extra Help program, which helps people with low incomes pay Part D premiums and out-of-pocket costs. You can change Part D plans as often as once each quarter.
• Find a Part D plan with a five-star rating in your area. You can make a one-time switch into that plan outside of open enrollment.

Only two Part D plans, insurers in parts of Pennsylvania and western New York, made the top grade for 2026. Both had fewer than 10,000 enrollees in 2025.

I don’t have Part D or Medicare Advantage. Now what?

You have several chances to sign up outside of open enrollment:

• During your seven-month initial enrollment period for Medicare, the three months before the month you turn 65 until three months after your birthday month.
• Within two months of losing employer or union health insurance.
• Within two months of losing drug coverage considered at least as good as Part D, called “creditable coverage.” This creditable coverage may be from an employer, a retiree plan, Tricare or another source.

What do I do if I never signed up for Part A or Part B?

Open enrollment season is not meant for new Medicare enrollees, even if TV ads make it seem as if everyone 65 and older should be participating.

If you’re working or insured through a spouse who has a job now, as long as you sign up within eight months of losing that employer or union medical insurance, you will avoid a Part B late enrollment penalty. If you’re beyond the two-month window to sign up for Medicare Advantage or Part D, you’ll have to wait until Oct. 15, the start of the next open enrollment period, and could face a Part D late enrollment penalty if you don’t have creditable coverage in the meantime.

If you missed your initial enrollment period at age 65 or any special enrollment period you might have qualified for, you’ll have to wait to sign up from Jan. 1 to March 31, the general enrollment period.

After your coverage for Parts A and B begins, or just Part B if you already have Part A, you’ll have two months to pick a Part D plan or a Medicare Advantage policy with drug coverage without penalty. If you choose original Medicare, the month your Part B begins, you’ll start your six-month, once-in-a-lifetime Medigap open enrollment period when you can buy any policy in your area at the best rate for someone your age.

Be aware: You may have to pay late enrollment penalties for Part A or Part B, depending on your circumstances.

Does Medicare have any exceptions?

If you can’t sign up for Part A or Part B because of an exceptional condition, such as being unable to complete your registration in time because of a natural disaster, misinformation from your employer or losing Medicaid coverage, you’ll have two months after you enroll to join a Medicare Advantage plan or a Part D prescription plan. Coverage will start on the first of the month after the plan receives your request to join.

If you don’t apply for prescription drug coverage from a Part D or Medicare Advantage plan within these time frames and don’t have other creditable drug coverage, you may have to pay a lifetime Part D late enrollment penalty when you sign up.

Still confused? Counselors who work for State Health Insurance Assistance Programs, known as SHIP, are available in every state and the District of Columbia, Guam, Puerto Rico and the U.S. Virgin Islands. They provide free, unbiased, one-on-one advice about Medicare.

This story, originally published Dec. 6, 2022, was updated with information for the 2026 Medicare plan season.