In short
- Annual Enrollment for 2027 plans runs October 15 to December 7, 2026, and changes start January 1, 2027.
- Your Initial Enrollment Period is 7 months: 3 before your 65th birthday month, the month itself, and 3 after.
- The Medicare Advantage Open Enrollment Period (January 1 to March 31) allows one change, only for people already in Medicare Advantage.
- Your 6-month Medigap Open Enrollment Period starts when you are 65 and have Part B. It happens once and does not repeat.
- Missing the right window can mean a coverage gap and a permanent late penalty.
Medicare does not let you sign up or switch whenever you like. It uses enrollment periods: fixed windows each year, a personal window around your 65th birthday, and special windows triggered by life events. Here is every one of them, what you can do in each, and the dates for the 2027 plan year.
What are all the Medicare enrollment periods?
There are seven main windows. Two are about getting Parts A and B, three are about choosing or changing private plans, one is for Medigap, and one family of windows (Special Enrollment Periods) covers life changes.
| Enrollment period | When | What you can do | When coverage starts |
|---|---|---|---|
| Initial Enrollment Period (IEP) | 7 months around your 65th birthday month | Sign up for Parts A and B; join a Medicare Advantage or Part D plan | Your birthday month if you sign up early; otherwise the month after you sign up |
| General Enrollment Period (GEP) | January 1 to March 31 each year | Sign up for Part B (or premium Part A) if you missed your IEP and have no SEP | The month after you sign up; penalties may apply |
| Part B Special Enrollment Period (employer) | While covered by a current employer plan, plus 8 months after the job or coverage ends | Sign up for Part A and/or B without a penalty | Usually the month after you sign up |
| Annual Enrollment Period (AEP) | October 15 to December 7 | Join, switch or drop Medicare Advantage or Part D; move between Original Medicare and Medicare Advantage | January 1 |
| Medicare Advantage Open Enrollment (MA OEP) | January 1 to March 31 (or your first 3 months with A and B, if new) | One change: a different Medicare Advantage plan, or back to Original Medicare plus Part D | The month after the plan gets your request |
| Special Enrollment Periods (SEPs) | Triggered by events: moves, lost coverage, Medicaid or Extra Help, 5-star plans and more | Depends on the event | Usually the month after you enroll |
| Medigap Open Enrollment | 6 months starting the first month you are 65 or older and have Part B | Buy any Medigap policy sold in your state with no health questions | As soon as the policy is issued |
What happens during your Initial Enrollment Period?
Your Initial Enrollment Period (IEP) is your first chance to sign up for Medicare. It lasts 7 months: the 3 months before your 65th birthday month, your birthday month, and the 3 months after. If your birthday falls on the 1st, the window shifts one month earlier.
Signing up in the first 3 months gets you coverage on the first day of your birthday month. Signing up later in the window means coverage starts the month after you sign up. Our Initial Enrollment Period guide has a month-by-month table, and the enrollment calculator shows your exact dates.
If you are already getting Social Security at least 4 months before 65, you are enrolled in Parts A and B automatically. You still use your IEP to choose a Medicare Advantage or Part D plan.
When is Annual Enrollment for 2027 plans?
The Annual Enrollment Period (AEP), which Medicare calls Open Enrollment, runs October 15 to December 7, 2026 for coverage that starts January 1, 2027. During it, you can:
- Switch from Original Medicare to Medicare Advantage, or back
- Switch from one Medicare Advantage plan to another
- Join, switch or drop a standalone Part D plan
- Add or drop drug coverage
Key dates around this year's window:
| Date | What happens |
|---|---|
| By September 30, 2026 | Medicare Advantage plans send members an Annual Notice of Change (ANOC) for 2027 |
| October 1, 2026 | 2027 plans appear on Medicare.gov's Plan Finder |
| On or around October 8, 2026 | CMS posts 2027 Star Ratings |
| October 15, 2026 | Annual Enrollment opens |
| December 7, 2026 | Last day to make a change |
| January 1, 2027 | New coverage starts |
For 2027, CMS says Nebraska has 48 Medicare Advantage plans (down from 50) and 9 standalone Part D plans. Plan availability, premiums, networks and benefits vary by county and change every year, which is why a yearly review is worth the time. Here is what a good annual enrollment review covers.
What is the Medicare Advantage Open Enrollment Period?
The Medicare Advantage Open Enrollment Period runs January 1 to March 31 each year for people already in a Medicare Advantage plan. You get one change: switch to another Medicare Advantage plan, or drop Medicare Advantage and go back to Original Medicare, where you can also join a Part D plan.
It cannot be used to move from Original Medicare into Medicare Advantage, or to switch between standalone Part D plans. If you are new to Medicare and joined a Medicare Advantage plan, your version of this window runs through the end of your third month with both Part A and Part B. Details and examples are in our Medicare Advantage Open Enrollment guide.
What is the General Enrollment Period?
The General Enrollment Period, January 1 to March 31, is the catch-up window for people who missed their Initial Enrollment Period and do not qualify for a Special Enrollment Period. Since January 2023, coverage starts the first day of the month after you sign up.
Because you are signing up late, you will likely owe a Part B penalty: 10% for each full 12 months you went without Part B when you could have had it. If you sign up for Part B this way, you also get a short window to join a Medicare Advantage or Part D plan, from when you apply through your first 2 months of Part B. See late enrollment penalties for worked examples.
What are Special Enrollment Periods?
Special Enrollment Periods (SEPs) let you sign up or change plans outside the usual windows when something specific happens. The most common:
- Losing employer coverage. An 8-month window to sign up for Part B, and 2 full months after the coverage ends to join a Medicare Advantage or Part D plan.
- Moving out of your plan's service area: from the move through 2 full months after.
- Losing Medicaid: 3 full months to change plans.
- Medicaid or Extra Help: one change per calendar month for Part D (and, with full Medicaid, integrated plans).
- A 5-star plan: join it once between December 8, 2026 and November 30, 2027.
- Your plan leaving your area: Medicare gives you time to pick a new plan, and you may get guaranteed Medigap rights.
The full list, and the paperwork that proves each one, is in our Special Enrollment Periods guide.
When can you buy a Medigap policy?
Medigap does not follow Medicare's enrollment periods. Your one-time Medigap Open Enrollment Period is 6 months long and starts the first month you are 65 or older and enrolled in Part B. During it, an insurer must sell you any Medigap policy it offers in Nebraska at its standard price, regardless of your health.
After that window, you can apply any time of year, but outside a guaranteed issue situation the company can ask health questions and turn you down. Nebraska has no birthday rule or annual switching window. If you delay Part B because you are still working, your Medigap window waits too. See Medigap open enrollment in Nebraska.
Where can you check which window applies to you?
If you are not sure which enrollment period you qualify for, call 1-800-MEDICARE (1-800-633-4227), available 24 hours a day, 7 days a week (TTY 1-877-486-2048). Nebraska SHIP (formerly SHIIP) offers unbiased one-on-one counseling at 1-800-234-7119. If you want a licensed agent to look at your dates and your plan options together, talk to Bill.
Frequently asked questions
The Annual Enrollment Period for 2027 coverage runs October 15 to December 7, 2026. Any change you make takes effect January 1, 2027. Medicare.gov's Plan Finder has shown 2027 plans since October 1, 2026, and CMS expects to post 2027 Star Ratings on or around October 8, 2026. For a January 1 start, the plan must get your request by December 7.
No. Outside your Initial Enrollment Period, you can generally change Medicare Advantage or Part D plans only during Annual Enrollment (October 15 to December 7), the Medicare Advantage Open Enrollment Period (January 1 to March 31, one change), or a Special Enrollment Period triggered by a qualifying event like a move, losing other coverage, or getting Extra Help or Medicaid.
They share dates, January 1 to March 31, but do different things. The General Enrollment Period is for people who missed signing up for Part B (or premium Part A) and have no Special Enrollment Period; coverage starts the next month and penalties may apply. The Medicare Advantage Open Enrollment Period lets people already in a Medicare Advantage plan make one plan change.
Annual Enrollment does not apply to Medigap. Medigap policies are not part of Medicare's enrollment periods. You can apply to change a Medigap policy any time of year, but outside your one-time Medigap Open Enrollment Period or a guaranteed issue situation, the insurer can review your health and decline you. Nebraska has no birthday rule or annual Medigap switching window.
If you are in a Medicare Advantage plan on January 1, the Medicare Advantage Open Enrollment Period lets you make one more change by March 31, either to a different Medicare Advantage plan or back to Original Medicare with a standalone Part D plan. If you chose Original Medicare with a Part D plan, that window does not apply, and you would generally wait for a Special Enrollment Period or next fall.
Sources
- Medicare.gov: Understanding Medicare Advantage and drug plan enrollment periods (11219) (opens in a new tab)
- Medicare.gov: When does Medicare coverage start? (opens in a new tab)
- Medicare & You 2027 handbook (CMS Product 10050) (opens in a new tab)
- Medicare.gov: Choosing a Medigap Policy (02110) (opens in a new tab)
- CMS: 2027 Medicare Advantage and Part D state fact sheets (opens in a new tab)
We do not offer every plan available in your area. Any information we provide is limited to those plans we do offer in your area. Please contact Medicare.gov or 1-800-MEDICARE to get information on all of your options. 1-800-MEDICARE (1-800-633-4227) is available 24 hours a day, 7 days a week. TTY users can call 1-877-486-2048.
