Medicare Advantage

What’s Changing in Colorado Medicare Advantage for 2027: 30 Plans Leaving, 31 Changing

DENVER — Colorado's Medicare Advantage lineup is shifting again for the 2027 plan year, and most of the state will feel at least some of the change. According to the CMS Medicare Advantage Landscape Source Files for CY2026 and CY2027, Colorado will go from 107 Medicare Advantage plans offered in 2026 to 104 offered in 2027. Behind those headline numbers: 30 plans are leaving, 31 are changing in at least one county, 27 are new, and 46 are continuing unchanged. All 64 Colorado counties see at least one plan leave or change.

Here is what Coloradans on Medicare need to know before the Annual Enrollment Period closes on December 7, 2026.

What the statewide numbers mean

The CMS Medicare Advantage Landscape Source Files list every Medicare Advantage plan offered in Colorado for a given plan year. Comparing the CY2026 and CY2027 files, each plan counted once statewide no matter how many counties it serves, Colorado's totals look like this:

• 107 plans offered in 2026; 104 offered in 2027.
• 30 plans are "leaving" — offered somewhere in Colorado for 2026 but nowhere for 2027.
• 31 plans are "changing" — offered in both years, but with a different premium, drug deductible, plan type or plan name in at least one county.
• 27 plans are new for 2027.
• 46 plans continue unchanged.

CMS defines "leaving" strictly: the plan does not appear in Colorado at all in the 2027 file. "Changing" means the plan is still available in Colorado in 2027, but at least one of those four fields — premium, drug deductible, plan type or plan name — is different in at least one county. One carrier, Clear Spring Health, has no Colorado plans listed for 2027.

If your plan is leaving

If your current Medicare Advantage plan is one of the 30 leaving Colorado for 2027, two things apply.

First, you will receive a non-renewal notice from your plan. You then qualify for a Special Enrollment Period (SEP) that runs through the end of February 2027. That SEP gives you extra time, beyond the standard Annual Enrollment Period, to pick a new Medicare Advantage plan or return to Original Medicare and, if you choose, add a stand-alone Part D drug plan.

Second, if you do nothing, you cannot stay in a plan that no longer exists. Depending on your situation, you may end up back in Original Medicare without drug coverage. That is why reading the non-renewal letter — and acting during AEP or your SEP — matters.

If your plan is changing

If your plan is one of the 31 that CMS flags as changing for 2027, it is still being offered, and if you do nothing you will stay enrolled in it on January 1, 2027, with whatever changes are described in your Annual Notice of Change (ANOC).

The ANOC is the document to read. By CMS rules, it lays out the specifics of what is different between your 2026 plan and your 2027 plan. We are not going to characterize those changes here, because the Landscape file only tells us that something changed — the ANOC tells you exactly what, and by how much, for your plan and your county.

If the changes do not work for you, the Annual Enrollment Period (October 15 – December 7, 2026) is your window to switch.

Counties with the most change

Every Colorado county sees at least one plan leave or change for 2027. The counts below come from the CMS Landscape comparison and reflect how many plans are leaving and changing in each of these counties:

• Clear Creek County: 31 leaving, 13 changing
• Elbert County: 26 leaving, 13 changing
• Douglas County: 24 leaving, 19 changing
• Boulder County: 19 leaving, 19 changing
• Denver County: 18 leaving, 22 changing
• Jefferson County: 18 leaving, 22 changing
• Adams County: 17 leaving, 22 changing
• Arapahoe County: 17 leaving, 21 changing

A plan counted as "leaving" in your county may still be sold elsewhere in the country; what matters locally is that it will not be available to you in 2027.

What to do before December 7

A short checklist for the weeks ahead:

1. Watch your mail in September and October 2026 for either a non-renewal notice (your plan is leaving) or an Annual Notice of Change (your plan is renewing, with or without changes). 2. If your plan is leaving, mark the SEP on your calendar — it runs through the end of February 2027 — but you can also use the Annual Enrollment Period, October 15 – December 7, 2026. 3. If your plan is changing, read the ANOC and decide whether the 2027 version still fits your doctors, your prescriptions and your budget. 4. If you want to make a change, do it during AEP so your new coverage starts January 1, 2027. 5. If you do nothing and your plan is renewing, you stay enrolled with the 2027 terms in the ANOC.

Where to get free help

You do not have to sort this out alone, and you do not have to pay anyone to help you compare plans.

• Medicare.gov has a Plan Finder tool where you can enter your ZIP code and prescriptions and see every 2027 Medicare Advantage and Part D plan available to you.
• 1-800-MEDICARE (1-800-633-4227) is open 24/7 for questions about enrollment, notices and your coverage options.
• The State Health Insurance Assistance Program (SHIP) offers free, unbiased, one-on-one Medicare counseling in Colorado. SHIP counselors can walk through your ANOC or non-renewal letter with you and help you compare plans in your county.

Sources: CMS — MA Landscape Source Files (CY2026 and CY2027 year-over-year comparison); CMS — MA/Part D Landscape & Plan Finder data.