How Medicare Advantage works
Medicare Advantage (also called Part C) is an alternative way to get your Medicare benefits. Instead of receiving coverage directly from the federal government (Original Medicare), you enroll in a plan offered by a private insurance company that contracts with Medicare.
These plans must cover at least everything Original Medicare covers (Parts A and B), and some also offer extra benefits. You still pay your Part B premium, and some plans charge an additional monthly premium.
Key difference: Unlike Original Medicare, which has no out-of-pocket maximum, all Medicare Advantage plans cap your annual out-of-pocket spending. In 2026, the maximum allowed by Medicare is $9,250 for in-network services; a plan may set a lower limit.
Types of Medicare Advantage plans
- HMO (Health Maintenance Organization) — Requires you to use doctors and hospitals within the plan's network except in emergencies. Usually requires a referral to see specialists.
- PPO (Preferred Provider Organization) — Lets you see any doctor, but you pay less when using in-network providers. No referrals needed for specialists.
- PFFS (Private Fee-for-Service) — Determines how much it will pay providers and how much you pay when you receive care. You can see any provider who agrees to the plan's terms.
- SNP (Special Needs Plan) — Designed for people with specific diseases, limited income, or who are dual-eligible for Medicare and Medicaid.
- HMO-POS (Point of Service) — An HMO that allows some out-of-network care at higher cost.
Extra benefits some Medicare Advantage plans offer
Medicare Advantage plans may offer extra benefits that Original Medicare doesn't cover, such as:
- Dental care
- Vision care
- Hearing care
- Fitness programs
- Transportation to medical appointments
- Telehealth
Extra benefits vary by plan and county, may have limits and costs, and not every plan offers them. Check a plan's Summary of Benefits or Evidence of Coverage.
Colorado tip: Plan availability varies a lot by county. For 2027, CMS lists 35 Medicare Advantage plans open to everyone in Denver County, 7 in Montrose County and none in 12 counties. Always compare plans for your specific ZIP code.
Pros and cons
Advantages:
- Out-of-pocket maximum protects you from catastrophic costs
- Some plans offer extra benefits, such as dental, vision and hearing (these vary by plan)
- Drug coverage can be part of the same plan
- One card, one plan — simpler to manage
Trade-offs:
- Provider networks limit which doctors and hospitals you can use
- May need referrals to see specialists (HMO plans)
- Coverage may not travel well if you spend time out of state
- Prior authorization may be required for some services
- Plan benefits can change every year at renewal
How to enroll in Medicare Advantage
You can enroll in a Medicare Advantage plan during:
- Initial Enrollment Period (IEP) — The 7-month window around your 65th birthday.
- Annual Election Period (AEP) — October 15 through December 7 each year. Coverage begins January 1.
- Open Enrollment Period (OEP) — January 1 through March 31. If you're already in a Medicare Advantage plan, you can switch to a different plan or return to Original Medicare.
- Special Enrollment Periods (SEP) — Available if you have qualifying life events like moving, losing employer coverage, or qualifying for Medicaid.
Frequently asked questions
What is Medicare Advantage?
Medicare Advantage (Part C) is an alternative to Original Medicare offered by private insurers. Plans bundle Parts A and B, and usually D. Some plans also offer extra benefits, such as dental, vision and hearing, which vary by plan and county.
How many Medicare Advantage plans are available in Colorado?
Plan availability varies by county. For 2027, CMS lists 35 Medicare Advantage plans open to everyone in Denver County, 13 in Mesa County (Grand Junction) and none in 12 counties. Each county page has its own count.
Do Medicare Advantage plans have an out-of-pocket maximum?
Yes. Unlike Original Medicare, all Medicare Advantage plans cap annual out-of-pocket spending. The 2026 maximum allowed by Medicare is $9,250 for in-network services.
