Medicare Advantage in Colorado (2027): How It Works

For 2027, 30 Medicare Advantage plans are leaving Colorado, 27 plans are new and 31 plans are changing, out of the 107 offered for 2026. This guide explains how the plans work in Colorado and what to compare — no rankings, no pressure.

One fact shapes every Medicare decision in Colorado: your county, not your state, sets your options. Neighboring counties can look surprisingly different, which is exactly why the guides here are local.

About 52% across Colorado have chosen Medicare Advantage over Original Medicare, though that share swings a lot depending on where you live.

Ahead: the companies active statewide, how Original Medicare, Advantage, Medigap and Part D fit together, the shared 2027 costs, enrollment windows, free unbiased help, and a guide for every Colorado city.

How your Medicare choices fit together

Almost everyone starts with Original Medicare — Part A (hospital) and Part B (medical), run by the federal government. From there, you generally choose one of two directions, and understanding the fork is the whole game.

The Medicare Advantage path (Part C). You get your Part A and Part B benefits through a private plan approved by Medicare, usually with drug coverage included. Plans work within networks and service areas set at the county level, which is why availability in Colorado depends on your county, not just your state.

The Original Medicare path. You stay with the government program and can add a stand-alone Part D drug plan, and often a Medigap policy to help with the out-of-pocket costs Original Medicare leaves behind — trading bundled extras for broad provider freedom.

Neither path is universally better; the right fit depends on your doctors, your prescriptions, your budget, and how you like to handle care. This guide explains how each works in Colorado so you can decide for yourself. We don't rank or recommend specific plans.

What Medicare costs in 2027

It helps to separate the costs everyone shares from the costs that vary by plan. The program-level numbers here are set nationally — the same whether you're in a big city or a rural county.

Part B premium. Most people pay the standard Part B premium of $202.90 a month in 2026 (2026 amount; 2027 figure will be posted when CMS releases it). Part A is premium-free for most people who worked and paid Medicare taxes long enough.

Part D drug costs. In 2027, a Part D plan's yearly deductible can be no more than $700, and a $2,400 cap limits what you pay out of pocket for covered prescriptions across the year — a real change for anyone with high drug costs.

Higher earners pay more for Parts B and D through an income-related adjustment called IRMAA, which for 2026 starts above $109,000 in annual income for an individual and is based on your 2024 tax return. Most people fall below that line and pay the standard amounts. The 2027 brackets will be posted when CMS releases them.

Plan-specific costs. What an individual plan charges — its premium, deductible, copays, and what it covers — varies by plan and changes yearly. We don't publish those figures or rank plans; Medicare's Plan Finder shows the current details for your situation, and a licensed agent can walk you through them.

When you can enroll or make changes

Medicare's enrollment windows are federal — the same nationwide — so the timing below applies wherever you live.

Your first window (IEP). When you're new to Medicare, your Initial Enrollment Period is the 7-month window around your 65th birthday month. Signing up on time helps you avoid late penalties that can follow you for years.

Annual Enrollment Period (AEP). Each fall, from October 15 – December 7, anyone with Medicare can join, switch, or drop a Medicare Advantage or Part D plan. Changes take effect January 1.

Medicare Advantage Open Enrollment. From January 1 – March 31, if you're already in an Advantage plan you get one chance to switch plans or return to Original Medicare.

Special Enrollment Periods can also open after certain life events, like moving or losing other coverage. The interactive calendar further down lays the year out visually.

Where to get free, unbiased help near Colorado

Good Medicare help exists and it's free — you don't have to figure this out solo or pay for guidance.

For official specifics and the Plan Finder tool, go straight to Medicare.gov or 1-800-MEDICARE (TTY 1-877-486-2048). And a licensed agent can compare options and handle the paperwork with you.

One note on who we are: MyMedicarePlans.org is an independent, privately owned educational resource — not Medicare, not a government agency, and not affiliated with one. Our job is to help you get oriented, then hand you off to the official sources and licensed professionals for plan decisions.

Colorado cities

Pick your city for the county-level picture, the companies active in your area, and local guides: