Medicare Supplement

Medigap in Boise: which plan letters you can still buy in Idaho

Boise, Idaho — If you have Original Medicare and you're weighing a Medicare Supplement policy, the first thing to know is that Medigap is built on a set of standardized plan letters. Idaho follows the federal standardization, so a Plan G sold by one company covers the same core benefits as a Plan G sold by another. What changes is the company behind it, the pricing method, and how the policy fits with your Part B and Part D coverage.

Boise is in Ada County, where the Medicare.gov Medigap policy search recently listed 16 insurers offering coverage in ZIP 83702. That gives shoppers a real range of choices across most of the standardized letters.

How the standardized letters work

Medigap policies sold in Idaho are federally standardized. That means the benefits inside a Plan G, a Plan N or a Plan K are set by Medicare, no matter which insurer sells the policy. Massachusetts, Minnesota and Wisconsin standardize differently, but Idaho does not — the letter tells you what the policy covers.

The letters available to people newly eligible for Medicare today are A, B, D, G, G-HD, K, L, M and N. Plans C and F remain available only to people who became eligible for Medicare before January 1, 2020. G-HD is a high-deductible version of Plan G; you pay Medicare-covered costs out of pocket until you meet the deductible, then the plan pays as a regular Plan G would.

Because the benefits inside each letter are the same across companies, the differences between insurers come down to price, customer service, and how they set premiums (for example, by age at issue, by attained age, or on a community-rated basis).

How Medigap pairs with Original Medicare and Part D

Medigap is a supplement, not a replacement. You keep Original Medicare as your primary coverage, and the Medigap policy fills in some of the deductibles, copays and coinsurance that Parts A and B leave behind. Which gaps it fills depends on the letter you buy.

Medigap does not include prescription drug coverage. If you want help with drug costs, you'll enroll separately in a standalone Part D plan. A few 2026 Part D facts worth knowing:

• The Part D out-of-pocket cap is $2,100 for 2026.
• The Part D maximum deductible is $615.
• The old coverage gap ("donut hole") was eliminated as of 2025, leaving three phases.
• The Medicare Prescription Payment Plan lets you spread drug costs across the year in monthly amounts.
• IRMAA surcharges (higher Part B and Part D premiums for higher earners) begin above $109,000 in income for a single filer in 2026.

You cannot be enrolled in a Medicare Advantage plan and a Medigap policy at the same time — Medigap is only for people on Original Medicare.

Enrollment timing and Idaho rules

The strongest federal protection for buying Medigap is your Medigap Open Enrollment Period: the six months that start the month you're 65 or older and enrolled in Part B. During that window, insurers must sell you any Medigap policy they offer at their best available rate, regardless of your health history.

Outside that window, in most cases, insurers in Idaho can use medical underwriting to decide whether to sell you a policy and at what price. Some states have added protections, such as annual "birthday rule" switching windows, but those rules vary and change over time. For a current answer about your rights in Idaho — including any state-specific guaranteed-issue situations — check with the Idaho Department of Insurance or SHIBA, the state's free counseling program.

Note that Medigap enrollment is not tied to Medicare's Annual Enrollment Period (October 15 – December 7) or the Medicare Advantage Open Enrollment Period (January 1 – March 31). Those windows apply to Advantage and Part D, not to Medigap.

Which insurers sell Medigap in Idaho

The table below lists every Medigap insurer active in Idaho and the plan letters each one offers. A few things to notice as you scan it:

• Not every insurer sells every letter. For example, Blue Cross of Idaho, Moda Health Plan, Inc., Mutual of Omaha (Omaha Insurance Company) and USAA Life Insurance Company each offer a selection of letters rather than the full menu.
• Some insurers — such as AARP - UnitedHealthcare Insurance Company, Humana Value (HumanaDental Insurance Company) and United American Insurance Company — list a longer set of letters, including Plans C and F, which are only available to people eligible for Medicare before January 1, 2020.
• The high-deductible version of Plan G (G-HD) is offered by a subset of insurers, including Bankers Life (Underwritten by Washington National Insurance Company), Blue Cross of Idaho, Humana Value (HumanaDental Insurance Company), Insurance Company of North America, Moda Health Plan, Inc., Mutual of Omaha (Omaha Insurance Company) and United American Insurance Company.

Because the benefits inside each letter are federally standardized, comparing the same letter across two or three companies is usually the most useful way to shop.

How to decide, step by step

Here's a simple order of operations that works for most people:

1. Decide whether you want to stay on Original Medicare with a Medigap policy, or use Medicare Advantage instead. You can't combine them. 2. If Medigap is the route, pick the plan letter that matches how much cost-sharing you want to hand off to the insurer versus keep yourself. Plans G and N are the most common choices for newly eligible people; Plans K, L and G-HD trade lower premiums for more out-of-pocket exposure. 3. Once you've picked a letter, compare that same letter across insurers. Ask each about the pricing method (issue-age, attained-age or community-rated) and how they've adjusted rates historically. 4. Choose a standalone Part D plan separately to cover prescriptions. 5. Confirm your enrollment window. If you're inside your six-month Medigap Open Enrollment Period, use it — that's your strongest guaranteed-issue right.

If you want unbiased help, SHIBA counselors in Idaho can walk through the choices with you at no cost.