By the Kryder Cares Data Desk · Reviewed by Kris Kryder, licensed agent · Updated
Key points
- Initial Enrollment Period: 7 months — 3 before your 65th-birthday month, that month, and 3 after.
- Open Enrollment for 2027 coverage runs Oct 15 – Dec 7, 2026; changes start Jan 1, 2027.
- Medicare Advantage members get one more change Jan 1 – Mar 31.
- Your Medigap Open Enrollment Period is a one-time 6-month window that starts with Part B at 65 or older.
Why the calendar matters
Medicare runs on enrollment periods: set windows when you can join, switch or drop coverage. Miss one and you may wait months for coverage and pay a late enrollment penalty for as long as you have Part B or Part D. The good news is that the windows are predictable, and most people only need to remember two or three of them.
| Window | When | What you can do |
|---|---|---|
| Initial Enrollment Period | 7 months around your 65th-birthday month | Sign up for Parts A and B; join a Medicare Advantage or Part D plan |
| Open Enrollment Period | Oct 15 – Dec 7 each year | Join, switch or drop Medicare Advantage or Part D; coverage starts Jan 1 |
| Medicare Advantage Open Enrollment | Jan 1 – Mar 31 (if already in Medicare Advantage) | Switch Medicare Advantage plans, or return to Original Medicare and add Part D |
| General Enrollment Period | Jan 1 – Mar 31 each year | Sign up for Part B if you missed your window; coverage starts the month after you sign up |
| Special Enrollment Periods | Varies with the life event | Sign up or change plans after a move, loss of coverage, Medicaid or Extra Help |
| Medigap Open Enrollment | 6 months from the first month you have Part B and are 65+ | Buy any Medigap policy sold in your area without medical underwriting |
Your Initial Enrollment Period
Your Initial Enrollment Period (IEP) lasts 7 months: it starts 3 months before the month you turn 65, includes your birthday month and ends 3 months after. During the IEP you can sign up for Part A and Part B and join a Medicare Advantage (Part C) plan or a stand-alone Part D drug plan.
Timing changes your start date. Signing up in the 3 months before your birthday month means coverage can begin the first day of your birthday month. Signing up later in the window delays it. If you join a Medicare Advantage plan during your IEP, you can switch plans or go back to Original Medicare within your first 3 months of having Parts A and B.
Want your own dates? Our enrollment window finder lays out your IEP month by month.
The Open Enrollment Period, October 15 – December 7
Every fall, everyone with Medicare can review and change coverage. For 2027 plans, Open Enrollment runs October 15 to December 7, 2026, and the plan must receive your request by December 7 for coverage to start January 1, 2027. You can switch Medicare Advantage plans, move between Original Medicare and Medicare Advantage, or join, switch or drop a Part D plan.
Plans change every year — premiums, drug lists, networks and copays. Your plan mails an Annual Notice of Change in late September; read it, then compare. Our 2027 Open Enrollment checklist lists what to look for.
Medicare Advantage Open Enrollment, January 1 – March 31
If you’re already in a Medicare Advantage plan on January 1, you get one more chance to change between January 1 and March 31. You can switch to a different Medicare Advantage plan, or drop it and return to Original Medicare and join a separate Part D plan. A change takes effect the first of the month after the plan gets your request.
This window doesn’t let someone in Original Medicare join Medicare Advantage, and it doesn’t open a guaranteed right to buy a Medigap policy.
The General Enrollment Period and Special Enrollment Periods
If you missed your IEP and don’t qualify for a Special Enrollment Period, you can sign up for Part B during the General Enrollment Period, January 1 – March 31. Coverage starts the month after you sign up, and you may owe a late enrollment penalty. Our penalties guide explains how that’s figured.
Special Enrollment Periods (SEPs) open after certain life events. The one most people use is the 8-month Part B SEP that starts when you or your spouse stop working or lose job-based coverage, whichever comes first. COBRA does not extend it. Other SEPs follow a move out of your plan’s area, a plan leaving your county, or qualifying for Medicaid or Extra Help.
The Medigap window most people only get once
Your Medigap Open Enrollment Period is 6 months long and starts the first month you have Part B and are 65 or older. During it, a company can’t turn you down or charge you more because of your health. After it ends, companies in most cases can use medical underwriting. It doesn’t repeat every year, so if Original Medicare plus a Medicare Supplement interests you, plan for it. See Medicare Advantage vs. Medigap.
How Kris helps
Kris tracks these dates for her clients across Ohio, Michigan, Indiana and Florida. She can confirm which window you’re in, line up plans from the companies she represents and handle the paperwork on time. Learn more about Medicare Advantage or book a no-cost review.
Your next step
Have questions about your own situation? Contact Kris or schedule a no-cost meeting. You can also read more about Medicare Advantage, Medicare Supplement (Medigap) and Medicare Part D.
Sources
- CMS — Joining a plan (enrollment periods)
- CMS — When does Medicare coverage start?
- CMS — When can I sign up for Medicare?
- CMS — Working past 65
- CMS — Get Medigap basics
- CMS — Get ready to buy a Medigap policy
- CMS — Avoid late enrollment penalties
We do not offer every plan available in your area. Currently we represent 14 organizations which offer 119 products in your area. Please contact Medicare.gov or 1-800-MEDICARE to get information on all of your options. This is a proprietary website and is not associated, endorsed or authorized by the Social Security Administration, the Department of Health and Human Services or the Center for Medicare and Medicaid Services. This site contains decision-support content and information about Medicare, services related to Medicare and services for people with Medicare. If you would like to find more information about the Medicare program please visit the Official U.S. Government Site for People with Medicare located at www.medicare.gov.
This guide is general education, not a recommendation for any specific plan or policy. Figures were current as of October 19, 2026; plan details and government amounts change every year.