An enrollment period is a window of time when Medicare lets you sign up or make a change. Miss one, and you may have to wait, or pay more for as long as you have coverage. Here is each window in plain words.
| Period | When | What you can do |
|---|---|---|
| Initial Enrollment Period | 7 months: 3 months before your 65th birthday month, that month, and 3 months after | Sign up for Parts A and B, and pick a drug or Advantage plan |
| General Enrollment Period | January 1 to March 31 | Sign up for Parts A and B if you missed your first chance |
| Annual Enrollment Period | October 15 to December 7 | Join, switch or drop Advantage and Part D plans for next year |
| Medicare Advantage Open Enrollment | January 1 to March 31 | If you have an Advantage plan, switch to another one or go back to Original Medicare |
| Special Enrollment Periods | After certain life events | Sign up or change plans outside the usual windows |
| Medigap open enrollment | 6 months, starting the month you are 65 and have Part B | Buy any Supplement a company sells, with no health questions |
Initial Enrollment Period
This is your first chance to get Medicare. It lasts 7 months, starting 3 months before the month you turn 65 and ending 3 months after. Signing up in the months before your birthday month helps your coverage start without a gap. See our Turning 65 checklist.
General Enrollment Period
If you missed your Initial Enrollment Period and do not qualify for a Special Enrollment Period, you can sign up for Parts A and B from January 1 to March 31. Your coverage starts the month after you sign up. You may owe a late penalty.
Annual Enrollment Period
From October 15 to December 7 each year, you can join, switch or drop a Medicare Advantage plan or a Part D drug plan. Changes start January 1. Plans can change their costs, drug lists and networks each year, so this is a good time for a yearly check.
Medicare Advantage Open Enrollment
From January 1 to March 31, if you already have a Medicare Advantage plan, you can make one change. You can switch to a different Advantage plan, or go back to Original Medicare and add a Part D plan. This window is not for people who have Original Medicare only.
Special Enrollment Periods
Some life events open a Special Enrollment Period. Common ones include:
- Moving to a new address outside your plan's service area
- Losing job-based health coverage
- Your plan leaving your area or ending its contract with Medicare
- Moving into or out of a nursing home
- Getting Medicaid or Extra Help with drug costs
Each one has its own timing and rules. Call us and we will check which applies to you.
Medigap open enrollment
Your Medigap open enrollment period is 6 months long. It starts the first month you are 65 or older and have Part B. During this time, a company must sell you any Supplement it offers, and cannot say no or charge you more because of your health. It happens once and does not repeat each year.
Working past 65
If you or your spouse still have health coverage from a current job, you may be able to wait on Part B. It depends on the employer's size:
- 20 or more employees: the job's coverage usually pays first. Many people can wait on Part B without a penalty while they stay on that coverage.
- Fewer than 20 employees: Medicare usually pays first. If you do not have Part B, you could be left with large bills. Most people in this case should sign up for Part B at 65.
When the job or the coverage ends, whichever comes first, you have an 8-month Special Enrollment Period to sign up for Part B. That clock starts even if you take COBRA. COBRA and retiree coverage do not count as coverage from a current job, so do not wait on them.
For drugs, ask your employer if your plan is creditable coverage, meaning it is expected to pay at least as much as Medicare drug coverage. If it is, you can wait on Part D. Keep the letter that says so. Once that coverage ends, sign up for Part D soon to avoid a gap of 63 days or more.
Talk with your benefits office and call us before you decide. This is one of the most common places people get tripped up.
Late enrollment penalties
Part B penalty: if you do not sign up when you are first able, and you do not have coverage from a current job, your Part B premium may go up by 10% for each full 12 months you could have had Part B but did not. For most people, you pay this extra amount for as long as you have Part B.
Part D penalty: if you go 63 days or more in a row without Part D or other creditable drug coverage after your first chance to sign up, a penalty is added to your drug plan premium. It grows with each month you went without coverage, and it lasts as long as you have Medicare drug coverage, even if you switch plans.
See this year's premiums on our Medicare costs page.
Call us first
Dates and rules can be confusing. Before you change anything, call a local agent. It is free to work with us, and there is no pressure. Book a free review or call (816) 307-6165.
Questions people ask us
Can I change my Medicare Advantage plan any time?
No. Most changes happen during Annual Enrollment (October 15 to December 7) or the Medicare Advantage Open Enrollment Period (January 1 to March 31). A Special Enrollment Period may let you change at other times.
Is there a yearly window to switch Medicare Supplements?
Not under federal rules. You can apply for a new Supplement any time, but outside your Medigap open enrollment period the company can usually ask health questions. Missouri has an extra yearly rule. See Missouri vs Kansas.
What if I missed my Initial Enrollment Period?
You can usually sign up during the General Enrollment Period, January 1 to March 31. You may owe a late penalty. Call us and we will help you look at your choices.
My plan is leaving my area. What do I do?
You will get a letter from your plan. You have a Special Enrollment Period to pick a new plan. Call us first, and we will compare the plans we offer that cover your doctors.