Medicare Advantage in Centennial, Colorado: Your Plain-English 2027 Guide

21 Medicare Advantage plans in Arapahoe County are changing for 2027, 17 plans are leaving and 10 plans are new. Use this guide to see how the plans work in Centennial, Colorado and what to compare, in plain terms.

Medicare around Centennial can look different from the county next door, and that's by design: plans are approved county by county, and Centennial sits in Arapahoe County (part of Centennial area).

61 Medicare Advantage plans are available for 2027. Roughly 58% of people with Medicare in the county have chosen Medicare Advantage over Original Medicare, among the roughly 95,133 residents who are 65 or older.

You'll see who offers coverage nearby, how the pieces of Medicare fit, what things cost in 2027, when the enrollment windows open, and where to turn for free, unbiased guidance.

Advantage or Original Medicare? The basic fork

Every Medicare decision in Centennial, Colorado branches from one question: do you want your coverage delivered through a private Medicare Advantage plan, or do you want to stay with Original Medicare and build around it?

Go the Medicare Advantage route and a private plan (approved by Medicare) handles your Part A and Part B, typically folds in drug coverage — within a network and a county-based service area.

Stay with Original Medicare and you keep nationwide provider freedom, then usually add a stand-alone Part D drug plan and often a Medigap policy to cover what Original Medicare doesn't.

There's no single winner here — it comes down to your providers, your medications, and your budget. We explain the trade-offs and leave the choice to you; we don't rank plans.

The 2027 numbers, from shared to plan-specific

Start with what's fixed for everyone. The standard Part B premium is $202.90 per month in 2026 (2026 amount; 2027 figure will be posted when CMS releases it), and Part A is premium-free for most people who paid Medicare taxes long enough while working.

On the drug side, Part D has real guardrails for 2027: a deductible capped at $700 and, a hard $2,400 ceiling on your out-of-pocket costs for covered prescriptions — the old coverage gap is gone.

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.

Everything past that is plan-specific: the premiums, copays, and coverage details of an individual Advantage or Medigap plan change from plan to plan and year to year. Rather than quote or rank those, we point you to Medicare's Plan Finder and a licensed agent for your exact numbers.

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 Centennial

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.

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