Medicare Advantage Plans (Part C): How They Work, What They Cover & When to Enroll

Medicare Advantage plans—also called Part C—are private plans that provide your Part A and Part B benefits, and many include drug coverage (MAPD). They often add extras like dental, vision, or hearing.

At Medigap Sherpas, we compare plans, explain networks and costs, and help you enroll—clearly and without pressure.

What Is a Medicare Advantage Plan?

Medicare Advantage is an alternative way to receive Original Medicare benefits through a private insurer. You must have Part A and Part B and continue paying your Part B premium. You also must live in the plan’s service area.

Common plan types:

• HMO: Care through a network; referrals often required.
• PPO: Network preferred, but out-of-network allowed at higher cost.
• SNP: Special Needs Plans for certain conditions, Medicaid eligibility, or institutional care.

You cannot use a Medigap policy with Medicare Advantage.

What Medicare Advantage Plans Typically Cover

All Medicare Advantage plans cover everything Original Medicare covers (medically necessary Part A & B services). Many plans also include:

• Prescription drugs (MAPD)
• Dental, vision, hearing benefits (plan specific)
• Fitness programs or over-the-counter allowances
• Worldwide emergency/urgent care (varies by plan)

Coverage details, networks, and costs vary by plan and county.

Costs & Out-of-Pocket Protection

• You usually pay your Part B premium and possibly a plan premium.
• Services have copays/coinsurance based on plan rules.
• Each plan sets an annual in-network MOOP (maximum out-of-pocket) limit. After you hit it, covered Part A/B costs are $0 for the rest of the year.
• Out-of-network MOOP applies to PPOs if you go outside the network.

Who’s Eligible?

You’re typically eligible if you:

• Have Medicare Part A and Part B
• Live in the plan’s service area
• Do not have End-Stage Renal Disease unless a plan accepts ESRD or you qualify under current rules (many do now)

You can’t hold Medigap and Medicare Advantage at the same time.

Enrollment Windows (Know Your Timing)

• Initial Coverage Election Period (ICEP): Around your Part B start (often aligned with your 7-month IEP).
• Annual Enrollment Period (AEP): Oct 15–Dec 7; switch, join, or drop MA/MAPD for Jan 1 coverage.
• Medicare Advantage Open Enrollment (MA-OEP): Jan 1–Mar 31; one-time switch MA→MA or MA→Original Medicare (+/- Part D).
• Special Enrollment Periods (SEPs): Life events like moving, losing coverage, 5-Star plans, or qualifying assistance can open a temporary switch window.

Medicare Advantage vs. Medigap (Quick Comparison)

• Medicare Advantage (Part C):
  All-in-one plan with networks, copays, authorizations, and an annual MOOP. Often includes Part D and extras.
• Original Medicare + Medigap (+ Part D):
  Nationwide provider access where Medicare is accepted; no network referrals; predictable costs via Medigap; separate Part D plan.

Your choice depends on doctor access, travel, medications, risk tolerance, and budget.