How the plan-ending dates are figured

1. Open Enrollment: Oct 15 – Dec 7

“an individual … may change his or her election from an MA plan to Original Medicare or to a different MA plan … If an individual changes his or her election to Original Medicare, he or she may also elect a PDP.”

Coverage you choose in Open Enrollment starts Jan 1.

2. The plan-ending Special Enrollment Period: Dec 8 – last day of February

“It begins December 8 of the contract year and ends the last day of the following February.”

This is for a plan “non-renewed effective January 1 (i.e., termination or service area reduction)”. It does not start on the date of your letter. Requests received Dec 8–31 start Jan 1, in January start Feb 1, and in February start Mar 1. The legal basis is 42 CFR 422.62(b)(1) and, for drug plans, 42 CFR 423.38(c)(6).

3. Merged plans don't get it

“Individuals affected by MA or Part D plan consolidations are not eligible for this SEP because plan consolidations are not terminations nor non-renewals.”

4. If you do nothing: Original Medicare

“You'll be enrolled in Original Medicare if you don't join another Medicare Advantage Plan before your current plan ends.”

Original Medicare is Part A and Part B. Drug coverage needs a separate Medicare drug plan.

5. Medigap guaranteed issue: from your letter to 63 days after your plan ends

“the period beginning on the date that the individual receives a notice of termination and ending on the date that is 63 days after the date the applicable coverage is terminated”

Medicare's Medigap guide adds: “You only have this right if you switch to Original Medicare (rather than join another Medicare Advantage Plan).” and “Medigap policies can't start until your Medicare Advantage Plan coverage ends.” The guide says to apply “By the date in your plan's termination notice” and “No more than 63 days after your Medicare Advantage Plan coverage ends”; the tool shows the statute's start (the day you got your letter). Plans A, B, C, D, F or G can be offered; C and F only if you were eligible for Medicare before Jan 1, 2020. Massachusetts, Minnesota and Wisconsin use different standardized policies.

6. Trial rights

“Your rights may last for an extra 12 months under certain circumstances.”

If you joined Medicare Advantage when you were first eligible at 65 and you're in your first year, you can buy any Medigap policy sold in your state. If you dropped a Medigap policy to join your first Medicare Advantage plan less than a year ago, you can buy the same policy back if the company still sells it. The window is 60 days before your coverage ends to 63 days after. If a first-year plan ends and you join another Medicare Advantage plan without a gap, the trial right can carry over (up to 2 years from your first Medicare Advantage plan).

7. Medicare Advantage Open Enrollment: Jan 1 – Mar 31

In plain words: If you're in a Medicare Advantage plan, you can make one switch from Jan 1 to Mar 31: to another Medicare Advantage plan, or to Original Medicare with a drug plan.

8. Part D late penalty: 63 days in a row

“a continuous period of 63 days or longer … not covered under any creditable prescription drug coverage”

The penalty is 1% of the national base beneficiary premium for each full month without coverage, rounded to the nearest $0.10, added for as long as you have Part D (Medicare.gov). The 2027 base premium is $41.33 (CMS, Jul 28, 2026).

9. The 90-day notice

“Each Medicare enrollee by mail at least 90 calendar days before the date on which the nonrenewal is effective”

For a plan ending Dec 31, 2026, that means letters went out in early October. We never tell you your letter was late.