Medicare Open Enrollment 2026: October 15 to December 7
Medicare annual enrollment runs October 15 to December 7, 2026. Enrollees can switch between Original Medicare, Medicare Advantage and Part D plans, effective January 1, 2027.
The window and what it allows
Medicare's annual open enrollment period runs October 15 through December 7, and changes made during it take effect on January 1 of the following year. The dates are the same every year. The enrollment period that opens in the fall of 2026 is therefore the one that sets 2027 coverage — a distinction worth keeping straight when reading guides written in an earlier year.[1][2]
NCOA lists the changes available during this window: join or drop a Part D prescription drug plan; switch from Original Medicare to a Medicare Advantage plan; drop a Medicare Advantage plan and return to Original Medicare; switch to a different Medicare Advantage plan; or switch to a different Part D plan. In short, movement is allowed in every direction during the fall window.[1][2]
The January window is not a second chance for everyone
The most expensive misunderstanding about Medicare enrollment is treating the Medicare Advantage Open Enrollment Period (January 1 to March 31) as a general do-over for anyone who missed December 7. It is not. NCOA states it is «for people who are already enrolled in a private Medicare Advantage plan».[4]
The restriction is explicit. NCOA lists what is *not* possible in the January window, beginning with «Switch from original Medicare to a Medicare Advantage plan». So the winter period only moves people out of Medicare Advantage — to a different Advantage plan, or back to Original Medicare with the option to add a separate drug plan. Someone on Original Medicare who wanted to move to Medicare Advantage and missed December 7 cannot use January to do it.[4]
The two periods also differ in effective date. Changes made in the fall window all start January 1. The January-to-March window is an additional opportunity for existing Medicare Advantage enrollees rather than a repeat of the annual period.[1][4]
How the parts fit together
Program structure, per KFF's overview: Part A covers inpatient hospital and hospice care, Part B physician and outpatient services, Part C (Medicare Advantage) bundles A and B through private plans and usually adds drug coverage, and Part D covers prescription drugs. The enrollment choices above are essentially choices about how to receive these parts.[3]
Verified facts
Each fact is labelled with its evidence typeEach fact in this section carries its evidence type — either cross-checked against independent sources, or confirmed from a single authoritative record.
Medicare's annual open enrollment period runs October 15 to December 7 each year, with changes taking effect January 1 of the following year.[1][2] 2 sources · independent
During the annual open enrollment period, enrollees can switch between Original Medicare and Medicare Advantage, change Medicare Advantage plans, and join, drop or switch a Part D prescription drug plan.[1][2] 2 sources · independent
A separate Medicare Advantage Open Enrollment Period runs January 1 to March 31 and is limited to people already enrolled in a Medicare Advantage plan.[1][4] 2 sources · independent
Reported, not confirmed
Not cross-checked — do not read as factFrom here on: claims and speculation that are not cross-checked.
Medicare covered about 65 million people as of 2022 (57 million aged 65 and older, about 8 million younger people with disabilities).[3] single-source ×1 · KFF overview
Timeline
- Model
- claude-fable-5
- Time
- 08/19/2026, 15:40
- Body characters
- 2,104
- Sources
- 4 sources adopted
- Model
- claude-fable-5 (review passed)
- Time
- 08/19/2026, 15:55
- Verdict
- Passed
Show revision history (2)
| 08/19/2026, 15:40 | First authored (claude-fable-5) | Created |
| 08/19/2026 | New document — annual mega-search entering its rising window (enrollment opens in ~8 weeks). Source caveat recorded honestly: Medicare.gov, CMS and every insurer page (Humana, SelectQuote, NCOA, Medicare Rights) block automated access, so the statutory window is crossed via two Wikipedia articles (same outlet — flagged in body and here) plus KFF for program structure. Ops may upgrade sources if an accessible official page is found. | Updated |
Frequently asked
When is Medicare open enrollment for 2027 coverage?
October 15 to December 7, 2026. Changes made during that window take effect January 1, 2027. The dates are the same every year.[1][2]
If I miss December 7, can I switch in January instead?
Only if you are already in a Medicare Advantage plan. The January 1 to March 31 period is limited to existing Medicare Advantage enrollees, and NCOA states you cannot use it to switch from Original Medicare to a Medicare Advantage plan.
What can I change during the annual enrollment period?
Join, drop or switch a Part D drug plan; move from Original Medicare to Medicare Advantage; drop Medicare Advantage and return to Original Medicare; or switch between Medicare Advantage plans.[1][2]
What are Medicare Parts A, B, C and D?
Part A is inpatient hospital and hospice care, Part B is physician and outpatient services, Part C (Medicare Advantage) bundles A and B through private plans, and Part D covers prescription drugs.[3]
Official links
- Official Medicare.gov