Medicare Advantage

Medicare in Idaho Falls: Key 2026 Deadlines You Can't Miss

Idaho Falls Medicare deadlines for 2027: AEP, MA OEP, IEP, GEP, and how to avoid Part B and Part D late enrollment penalties.

IDAHO FALLS — If you live in Idaho Falls and you're sorting through Medicare choices for 2027, the calendar matters as much as the plan count. Bonneville County had 18 Medicare Advantage plans and 5 carriers offering Medicare Advantage with drug coverage for 2026; the 2027 lineup is in each plan's ANOC and on Medicare.gov's Plan Finder. None of those options helps if you miss the window to sign up or switch. This guide walks through the deadlines that apply to you, what happens if one slips by, and how the dates fit together.

The deadlines that shape your year

Medicare runs on a set of enrollment windows. Each one exists for a different reason, and each one has consequences if you miss it. Here are the ones most Idaho Falls readers need to know:

• Initial Enrollment Period (IEP): The seven-month window around your 65th birthday — three months before, your birthday month, and three months after.
• General Enrollment Period (GEP): January 1 – March 31, for people who missed their IEP for Part A or Part B.
• Annual Enrollment Period (AEP): October 15 – December 7, for choosing or changing Medicare Advantage and Part D plans.
• Medicare Advantage Open Enrollment Period (MA OEP): January 1 – March 31, for people already in a Medicare Advantage plan.
• Special Enrollment Periods (SEPs): Triggered by life events like moving, losing job-based coverage, or qualifying for Extra Help.

Turning 65 in Idaho Falls? Start with your IEP

Your Initial Enrollment Period is your first — and cleanest — chance to sign up without penalty. It lasts seven months and centers on your 65th birthday month.

If you enroll during the three months before your birthday, coverage usually starts the first day of your birthday month. Wait until later in the window and coverage starts the month after you sign up. If you're still working and have health coverage from a large employer, you may be able to delay Part B without a penalty — but this is exactly the kind of question worth checking with the Social Security Administration or Idaho's SHIBA counselors before you assume anything.

What happens if you miss a deadline

This is the part that trips people up. Medicare penalties are not a one-time fine — they are added to your premium, often for as long as you have coverage.

• Part B late enrollment penalty: 10% added to your Part B premium for every full 12-month period you could have had Part B but didn't. It sticks with you for life.
• Part D late enrollment penalty: 1% of the national base beneficiary premium for every month you went without creditable drug coverage after you were first eligible. Also permanent.
• Missing AEP: You may be locked into your current plan for another year, unless a Special Enrollment Period applies.

If you missed your IEP entirely for Part B, the General Enrollment Period (Jan. 1 – Mar. 31) is the backup — but the late penalty may still apply.

How AEP and MA OEP work together

Think of these as two different doors, close together on the calendar.

Oct. 15 – Dec. 7 (AEP) is the big one. Anyone with Medicare can join, switch, or drop a Medicare Advantage or Part D plan. Changes take effect Jan. 1.

Jan. 1 – Mar. 31 (MA OEP) is narrower. It only helps people already enrolled in a Medicare Advantage plan. During this window you can switch to a different MA plan once, or drop MA and return to Original Medicare (and add a stand-alone Part D plan if needed). You cannot use MA OEP to join Medicare Advantage for the first time from Original Medicare.

One note for Bonneville County residents: Idaho has 10 stand-alone Part D plans for 2026, sold statewide, and anyone with Original Medicare in the county can join one of them. If you rely on Original Medicare and want drug coverage for 2027, confirm your options directly on Medicare.gov's Plan Finder.

Program-level changes to know for 2027

A few program-wide updates take effect regardless of which plan you choose:

• The Part D out-of-pocket cap is $2,100 in 2026 and $2,400 in 2027.
• The Part D maximum deductible is $615 for 2026 and $700 for 2027.
• The coverage gap (the old "donut hole") was eliminated in 2025, so Part D now has three phases.
• The Medicare Prescription Payment Plan lets you spread drug costs across the year in monthly payments — you have to opt in.
• IRMAA income surcharges start above $109,000 for a single filer in 2026.

Where to get free, local help

Bonneville County had 18 Medicare Advantage plans from 5 carriers for 2026, plus Original Medicare and Medigap choices to weigh. The 2027 lineup is in each plan's ANOC and on Medicare.gov's Plan Finder. That's a lot to sort through, and you don't have to do it alone.

• Medicare.gov — the official plan finder and rulebook.
• 1-800-MEDICARE — 24/7, live help.
• Idaho SHIBA (Senior Health Insurance Benefits Advisors), Idaho's SHIP — free, unbiased one-on-one counseling for Idaho Falls residents.