Open enrollment & Medicare AEP calendar (plain English)
Jordan Sarmiento · CEO
Last reviewed September 13, 2026
Educational only. Not medical, legal, or personalized insurance advice. Claims review by compliance when material claims change.
On this page
Open enrollment windows are short. Missing them usually means waiting — unless a Special Enrollment Period applies.
This page collects Marketplace Open Enrollment and Medicare Annual Enrollment Period (AEP) dates in one place, with links to the official sources. Always confirm on HealthCare.gov or Medicare.gov before you act.
Last reviewed: 2026-09-13 (dates pulled from HealthCare.gov / Medicare.gov / CMS materials for the 2026–2027 cycle).
Marketplace Open Enrollment
| Window | Who | When (2026–2027 cycle) | What it is for | Official source |
|---|---|---|---|---|
| Marketplace Open Enrollment | Most people shopping for ACA Marketplace coverage | November 1, 2026 – January 15, 2027 | Enroll in, renew, or change Marketplace plans for 2027 coverage | HealthCare.gov dates & deadlines |
| January 1 start deadline | Marketplace shoppers who want coverage to start January 1 | Enroll by December 15, 2026 | Last day for January 1 effective date (if you pay the first premium) | Same HealthCare.gov page |
| February 1 start | Marketplace shoppers who enroll later in OE | Enroll December 16, 2026 – January 15, 2027 | Coverage can start February 1 (if you pay the first premium) | Same HealthCare.gov page |
Note: If your state runs its own Marketplace (not HealthCare.gov), end dates can differ — always check your state site and confirm on HealthCare.gov dates & deadlines.
Outside Open Enrollment, Marketplace enrollment or plan changes usually require a Special Enrollment Period based on a qualifying life event (or other SEP rules). Medicaid and CHIP applications can happen year-round. See coverage outside Open Enrollment.
Job-based plans often use different employer OE windows — check with your employer.
Medicare Annual Enrollment Period (AEP)
| Window | Who | When (2026–2027 cycle) | What it is for | Official source |
|---|---|---|---|---|
| Medicare Open Enrollment / AEP | People with Medicare | October 15 – December 7, 2026 | Join, switch, or drop Medicare Advantage and/or Part D drug coverage; switch between Medicare Advantage and Original Medicare for 2027 (plan must receive your request by December 7) | Medicare.gov Open Enrollment |
| Compare ahead | People with Medicare | From October 1, 2026 | Start comparing 2027 plan options before AEP opens | Medicare.gov Open Enrollment / Medicare & You 2026 |
Changes made during AEP generally take effect January 1, 2027 when the plan receives a timely enrollment request.
Related Medicare windows
| Window | Who | When | What it is for | Official source |
|---|---|---|---|---|
| Medicare Advantage Open Enrollment Period (MA-OEP) | People already in a Medicare Advantage Plan | January 1 – March 31 each year | Switch to another Medicare Advantage Plan, or switch to Original Medicare (and usually join a separate drug plan). You generally cannot use MA-OEP to move from Original Medicare into Medicare Advantage. | Medicare.gov / Medicare & You handbook |
| General Enrollment Period (Part A/B) | People who missed Initial Enrollment and do not have another SEP | January 1 – March 31 each year | Sign up for Part B (and Part A if you do not qualify for premium-free Part A). Coverage timing and possible late-enrollment penalties are on Medicare.gov. | Medicare.gov |
Medigap (Medicare Supplement) timing has separate guaranteed-issue and underwriting rules. This page does not replace Medigap advice — start at Medicare.gov Medigap materials if that is your question.
Special Enrollment Periods (overview)
SEPs exist for certain life events and situations (for example losing other coverage, moving, marriage, birth/adoption, and other qualifying events). Rules differ for Marketplace vs Medicare.
- Marketplace SEP overview: HealthCare.gov — coverage outside Open Enrollment
- Medicare plan-change timing: Medicare.gov Open Enrollment
This is not an exhaustive legal list. If you think you qualify, confirm on the .gov site that applies to you.
How to use this calendar in a Free Healthcare Review
Bring this page and your current cards or EOBs to a free healthcare review. Useful prep:
- Circle the next window that applies to you (Marketplace OE, Medicare AEP, MA-OEP, or a possible SEP).
- Write one sentence: what you want to change (or keep) before that deadline.
- Walk the healthcare review checklist so documents and questions are ready.
AFHC can help you organize a household plan conversation. Official enrollment still happens on HealthCare.gov, Medicare.gov, or your plan — we do not invent dates or promise outcomes.
Related research
- What underinsured means
- Catastrophic core + gap coverage explained
- Free healthcare review checklist
- Medicare coverage overview
FAQ
When is Marketplace Open Enrollment for 2027 coverage?
HealthCare.gov states Open Enrollment for 2027 coverage starts November 1, 2026 and runs through January 15, 2027. Enroll by December 15, 2026 for a January 1 start, or by January 15 for a February 1 start (if you pay the first premium). Always re-check HealthCare.gov.
When is Medicare Annual Enrollment Period (AEP)?
Medicare Open Enrollment / AEP runs October 15 through December 7. For the 2026–2027 cycle, that is October 15–December 7, 2026, with changes generally effective January 1, 2027 when the plan receives a timely request. Confirm on Medicare.gov.
What is the Medicare Advantage Open Enrollment Period (MA-OEP)?
If you are already in a Medicare Advantage Plan, MA-OEP (January 1–March 31) lets you switch to another Medicare Advantage Plan or switch to Original Medicare (often with a separate drug plan). It is not the same as AEP. See Medicare.gov.
Can I enroll outside these windows?
Sometimes, through a Special Enrollment Period if you qualify. Marketplace and Medicare SEP rules differ. Start with HealthCare.gov or Medicare.gov — do not rely on an unofficial date list.
Does AFHC enroll me on HealthCare.gov or Medicare.gov for me?
Official enrollment actions happen through government or plan channels. A free healthcare review can help you prepare documents, questions, and timing. It is educational help, not a guarantee you will beat a deadline or lower a premium.
Method / disclaimer
Dates above were assembled from HealthCare.gov and Medicare.gov / CMS consumer materials on 2026-09-13. Government sites update. Verify before you act. This page is educational only — not medical, legal, or personalized insurance advice.
Next step
If you want help walking your calendar and paperwork in plain English, start a free healthcare review.
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