Medicare Supplement

Medigap in Denver: which standardized plan letters Coloradans can still buy

DENVER — If you have Original Medicare and you're shopping for a Medicare Supplement policy in Denver, the first thing to know is that Medigap plans are standardized by the federal government. That means a Plan G is a Plan G no matter which insurance company sells it. What changes from company to company — and sometimes from ZIP code to ZIP code inside Denver County — is the price and the way the price is set.

Medicare SupplementDenver, CO

Colorado follows the standard federal Medigap lettering (unlike Massachusetts, Minnesota and Wisconsin, which use their own system). So your job as a shopper isn't to decode different benefits at each company. It's to pick the letter that fits your budget and health, then compare the companies selling that letter in your area.

The plan letters you can buy in Colorado

Federal law sets ten standardized Medigap letters: A, B, C, D, F, G, high-deductible F, high-deductible G, K, L, M and N. Two of them — Plans C and F — are only available to people who were eligible for Medicare before January 1, 2020. If you turned 65 after that date, those two are off the table.

That leaves Denver shoppers who are newly eligible with Plans A, B, D, G, high-deductible G, K, L, M and N. Each letter covers a different mix of Part A and Part B cost-sharing (things like coinsurance, hospital days, and the Part B deductible). Plans K and L cap what you pay out of pocket each year but cover a smaller share of costs along the way. Plan N generally has lower premiums than Plan G but asks you to pay small copays for some office and emergency room visits.

Medicare.gov publishes a benefit-by-benefit chart that shows exactly what each letter covers. It's worth reading side by side with your own doctor bills before you pick.

How Medigap fits with Original Medicare and Part D

Medigap is designed to sit on top of Original Medicare. Medicare pays its share first, then your Medigap policy pays some or all of what's left, depending on the letter. You can use any doctor or hospital in the country that accepts Medicare.

A few important pairings to keep straight:

• Medigap does not work with Medicare Advantage. You can't use both at the same time, and you generally can't even buy a Medigap while enrolled in an Advantage plan.
• Medigap does not include prescription drug coverage. If you want drug coverage, you enroll in a stand-alone Part D plan.
• For 2026, Part D has a $2,100 out-of-pocket cap and a maximum deductible of $615. The old coverage gap ("donut hole") was eliminated in 2025, and Medicare now offers an optional Prescription Payment Plan that spreads your drug costs across the year.

If your income is above $109,000 as a single filer in 2026, you may also owe an IRMAA surcharge on Part B and Part D — that's separate from your Medigap premium.

The Colorado rules that shape your choice

Two things about Colorado are worth knowing before you sign anything.

Pricing method matters. Insurers can price Medigap policies in one of three ways: community-rated (everyone in the plan pays the same regardless of age), issue-age rated (based on your age when you bought it), or attained-age rated (rises as you get older). Two policies with the same letter can behave very differently over ten years depending on which method the company uses. The Colorado Division of Insurance publishes a rate guide that lists the method for each company.

Guaranteed issue windows are narrow. During your six-month Medigap open enrollment period — the one that starts when you're 65 and enrolled in Part B — a company cannot turn you down or charge you more because of your health. Outside that window, insurers in most cases can medically underwrite you, meaning they can decline you or price the policy higher based on your health history. Federal law also gives you guaranteed issue rights in a handful of specific situations (for example, if a Medicare Advantage plan leaves your area). Colorado may have additional protections; the state Division of Insurance and the Colorado SHIP (called SHIP Colorado) are the right places to confirm what applies to you.

How to find the companies selling Medigap in Denver County

Denver is in Denver County, and Medigap availability in Colorado is set by the state and by ZIP code. There is no single "Denver list" you should trust from a marketing site. Instead:

1. Go to medicare.gov and use the Medigap policy search. Enter your Denver ZIP code and it will show the letters and the companies licensed to sell them at your address. 2. Check the Colorado Division of Insurance Medigap rate guide for a side-by-side comparison of premiums and pricing methods. 3. Call SHIP Colorado, the state's free counseling program for people on Medicare, for one-on-one help. They don't sell anything.

The table below lists every plan letter available to newly eligible Coloradans; use it to narrow the letter first, then compare companies.

Timing: when to shop, when to switch

Your best-priced shot at Medigap is almost always during your initial six-month Medigap open enrollment period. After that, switching letters or companies usually means answering health questions.

Two dates people often confuse with Medigap timing:

• October 15 – December 7 is the Medicare Annual Enrollment Period. It's for Part D and Medicare Advantage — not Medigap. You can apply for a Medigap policy any time of year.
• January 1 – March 31 is the Medicare Advantage Open Enrollment Period, for people already in an Advantage plan.

If you're leaving Medicare Advantage to go back to Original Medicare plus Medigap, be careful — you may or may not have a guaranteed issue right to a Medigap policy depending on the specifics. Ask SHIP before you drop anything.