Medicare Advantage

Medicare in Idaho Falls: 2026 Plan Counts and the 2027 Part D Cap

IDAHO FALLS, Idaho — People turning 65 in Idaho Falls this fall have more than a dozen Medicare Advantage choices to sort through, and the program's own cost rules are shifting again in 2027. Idaho Falls is in Bonneville County, where 18 Medicare Advantage plans from 5 carriers were offered for 2026, according to the Centers for Medicare & Medicaid Services (CMS) Plan Finder data; the 2027 lineup is in each plan's Annual Notice of Change and on Medicare.gov's Plan Finder. Idaho has 10 stand-alone Part D plans for 2026, sold statewide, so anyone in the area with Original Medicare can join one of them; drug coverage can also be bundled into an Advantage plan (MA-PD).

That's a lot of paperwork to weigh — but the good news is that Medicare's cost structure is easier to compare in 2027 than it used to be. Here's how the pieces fit together.

Start with the four cost buckets

When you look at any Medicare choice, the money side breaks into four buckets:

1. Your monthly premium — what you pay just to have coverage. 2. Your deductible — what you pay before coverage kicks in. 3. Your cost-sharing — copays or coinsurance during the year. 4. Your out-of-pocket maximum — the ceiling that protects you in a bad year.

Every Medicare path — Original Medicare, a Medigap supplement, a Part D drug plan, or a Medicare Advantage plan — uses some version of these four buckets. Once you can see them side by side, 18 plans feels less overwhelming.

What the program itself sets for 2027

Some numbers are set by Medicare and don't change from plan to plan.

• Part B premium. Everyone with Part B pays a monthly premium set by CMS. Higher-income enrollees pay an Income-Related Monthly Adjustment Amount (IRMAA) on top, which begins above $109,000 in income for a single filer in 2026.
• Part D deductible cap. No Part D plan may charge a deductible higher than $615 in 2026.
• Part D out-of-pocket cap. Once you spend $2,100 out of pocket on covered drugs in 2026, you pay $0 for the rest of the calendar year. This is the single biggest change for people with heavy prescription costs.
• No more donut hole. As of 2025, the coverage gap is gone. Part D now has three phases: deductible, initial coverage, and catastrophic (where the cap ($2,100 in 2026, $2,400 in 2027) kicks in).
• Medicare Prescription Payment Plan. You can ask to spread your drug costs across the calendar year in level monthly payments instead of paying big amounts at the pharmacy counter. It doesn't lower the total — it smooths it.

These figures come straight from CMS and apply the same way in Idaho Falls as in the rest of the country.

Where the plan-by-plan cost differences show up

Once you know the program-level rules, the differences between the 18 Bonneville County Advantage plans mostly live in:

• Monthly plan premium (on top of Part B).
• Medical deductible, if any.
• Copays and coinsurance for doctor visits, hospital stays, and drugs.
• The plan's own in-network out-of-pocket maximum for medical care (separate from the $2,100 in 2026 ($2,400 in 2027) Part D cap).
• Whether the plan uses HMO or PPO rules for choosing providers.

Because the county has 5 carriers offering MA-PD, most people will be comparing several plans from a handful of insurers. The Medicare Plan Finder at medicare.gov lets you enter your prescriptions and preferred pharmacies and see estimated yearly costs for each plan — that is the honest way to compare, since drug lists and pharmacy pricing vary.

Original Medicare + Medigap: a different cost shape

If you stay with Original Medicare (Parts A and B) and add a Medigap policy plus a stand-alone Part D plan, your cost shape is different: usually a higher fixed monthly premium, but very predictable bills at the doctor and hospital. Idaho Falls residents have both paths open to them. Neither is universally cheaper — it depends on your health, your prescriptions, and how much predictability you want.

A quick word on star ratings

CMS rates Medicare Advantage and Part D contracts on a 1-to-5 scale for quality and customer experience. Under CMS's 2026 Star Ratings, 3 of the Medicare Advantage contracts offering plans in Bonneville County are rated 4 stars or higher; the 2027 ratings are on Medicare.gov's Plan Finder. Ratings are one data point among many — they measure things like customer service, appeals handling, and preventive care — and they don't tell you whether a plan fits your budget or covers your doctors.

Dates to circle

• Oct. 15 – Dec. 7, 2026: Annual Enrollment Period. Choose or switch plans for 2027 coverage.
• Jan. 1 – Mar. 31, 2027: Medicare Advantage Open Enrollment. If you're already in an Advantage plan, you get one chance to switch to a different one or return to Original Medicare.

Missing these windows can lock you into a plan for the year, or trigger late-enrollment penalties if you're new to Medicare.

Where to get unbiased help in Idaho Falls

• medicare.gov — the official Plan Finder, with 2027 pricing for every plan in Bonneville County.
• 1-800-MEDICARE (1-800-633-4227) — 24/7, free.
• Idaho SHIBA — Idaho's State Health Insurance Assistance Program (SHIP). Trained counselors give free, one-on-one Medicare help and don't sell insurance. Call the Idaho Department of Insurance to find the counselor closest to Idaho Falls.