Medicare Annual Enrollment in Idaho: What to Do October 15 to December 7
Your Idaho-specific guide to Medicare's Annual Enrollment Period, what you can change, what to compare, and the deadlines that actually matter.
Medicare's Annual Enrollment Period (AEP) runs October 15 to December 7 every year. Whatever you choose during AEP takes effect January 1. For most Idahoans, this is the one window each year to change Medicare Advantage or Part D plans without a special qualifying event.
What you can do during AEP
- Switch from Original Medicare to a Medicare Advantage plan.
- Switch from Medicare Advantage back to Original Medicare.
- Change from one Medicare Advantage plan to another.
- Join, drop, or switch a Part D prescription drug plan.
What AEP does NOT do
AEP is not a Medigap (Medicare Supplement) enrollment window. Medigap has its own rules, your 6-month Medigap Open Enrollment at 65, the Idaho birthday rule each year, and limited guaranteed-issue rights. If you want to switch Medigap, that's a separate conversation.
What to actually compare each fall
- Your current plan's Annual Notice of Change (ANOC), mailed in late September. Read the premium, deductible, copay, and formulary changes for next year.
- Whether your doctors are still in-network for next year.
- Whether all your prescriptions are still on the formulary at the same tier.
- Whether a better-fitting plan launched in your Idaho county.
Dual-eligibles: AEP matters less for you
If you have Medicare + Idaho Medicaid, you have the Integrated SEP, you can change D-SNPs or MMCP plans once per quarter all year. AEP is still useful, but you're not locked in like everyone else.
Deadlines to remember
- Oct 15: AEP opens.
- Dec 7: AEP closes. Your January 1 coverage is locked in.
- Jan 1 to Mar 31: Medicare Advantage Open Enrollment, one chance to switch MA plans or return to Original Medicare.
Talk to a real person
Hometown Health is an independent Idaho Falls agency. We focus on Medicare, Medicaid, and dual-eligible coverage across Idaho.