What is Medicare Part C?
In short: Medicare Part C is Medicare Advantage, a Medicare-approved plan sold by a private company that takes over your Part A and Part B coverage. By law it has to cover at least as much as Original Medicare does.
Choosing a plan is the first decision. Using it well, once your parent is enrolled, is the one that eats evenings: booking the referral, chasing the equipment, following up after a hospital stay. Navigate Care explains how a navigator helps with that and what it may cost on its what you will pay page.
Most people never say "Part C" out loud. The card in your parent's wallet shows a brand name, an insurer's HMO or a plan called something like "Advantage Gold." Part C is the government's filing name for what sits behind that brand: a private company, approved by Medicare, selling the plan. It's worth knowing the day you're comparing your parent's plan against a hospital bill, a denial letter, or a plan someone else is trying to sell.
So what does signing up for one of these plans actually get your parent?
What Medicare Part C covers
A Medicare Advantage plan has to cover, at minimum, everything Original Medicare covers: Part A hospital stays and Part B doctor visits and outpatient care. That's the floor, not the ceiling. Most plans build in more.
Medicare.gov's own plan-type comparison lists extra benefits many Advantage plans add on top, things like dental, vision, hearing and wellness services that Original Medicare alone doesn't offer. Most plans also fold in Part D drug coverage, so your parent isn't shopping for a separate prescription plan afterward.
What it still won't do is cover custodial care, the help with bathing, dressing or meals that's often the thing a family actually needs day to day. Being a private plan doesn't move that line. Our Medicare Part B guide goes through what counts as medically necessary care versus daily living help, and the difference holds whether your parent is on Original Medicare or Part C.
Who can enroll in Part C
Two tests decide it, and Medicare.gov is specific about both. Your parent needs Part A and Part B already, both of them, not one. And the plan has to actually serve the place your parent lives. Every Advantage plan has a service area, and moving out of it is one of the main reasons someone ends up switched back to Original Medicare without meaning to.
One old rule is worth saying out loud, because it's still floating around online. For years, a person with end-stage renal disease, kidney failure needing regular dialysis, couldn't join a Medicare Advantage plan at all. That bar is gone. Medicare.gov's current page on joining a plan doesn't list it as a restriction; it mentions ESRD only as one of the conditions that can make someone eligible for Medicare earlier than 65. If a relative or a salesperson tells your family otherwise, that's out of date information, not a current rule. Our guide on who qualifies for Medicare covers the underlying eligibility tests in full.
The types of Part C plans
"Medicare Advantage" isn't one product. Medicare.gov's plan comparison sorts it into five types, and the differences between them are the ones that actually matter when your parent is choosing.
An HMO asks your parent to pick a primary care doctor, stay in network except for emergencies, and get a referral before seeing a specialist. A PPO drops both requirements. No referral, and your parent can see an out-of-network provider, usually for more money. A PFFS plan sets its own payment terms with providers and skips the primary doctor and referral rules too. A Special Needs Plan, or SNP, limits membership to people with a specific disease or circumstance and shapes its benefits and drug list around that group; every SNP has to include Part D coverage. An MSA is the odd one out. It pairs a high-deductible plan with a savings account and, unusually, carries no extra monthly premium beyond the Part B premium.
The five Medicare Advantage plan types, side by side
| Plan type | Primary doctor required? | Referral for specialists? | Out-of-network care? |
|---|---|---|---|
| HMO | Yes | Usually yes | Emergencies only |
| PPO | No | No | Yes, usually at higher cost |
| PFFS | No | No | Any provider accepting the plan's terms |
| SNP | Varies by structure | Varies by structure | Varies by structure |
| MSA | No | No | Yes, no network restriction |
Source: Medicare.gov, compare your coverage choices
For most families the real decision is HMO or PPO, the two types a parent is likeliest to see offered by name in their area. If your parent travels often, sees a specialist who sits outside a tight network, or just hates asking permission before an appointment, that pulls toward a PPO. If keeping the premium low and having one doctor coordinate everything sounds more like your parent, that pulls toward an HMO. SHIP, the free State Health Insurance Assistance Program, will walk through this trade-off without selling anything, and it's worth a call before signing.
What Part C costs
Your parent still pays the Part B premium either way. That doesn't go away just because they've picked a Part C plan. What changes is what's added on top of it, and in 2026, for most people, that's less than it sounds.
KFF's 2026 Medicare Advantage brief puts the average extra premium across individual Advantage plans with drug coverage at $15 a month, and says three quarters of people enrolled in those plans pay no premium at all beyond the standard Part B amount. That's the headline most families actually feel.
The number that matters more in a bad year is the out-of-pocket maximum, the yearly ceiling on what your parent pays for covered care before the plan picks up the rest. Original Medicare alone doesn't have one of these. Every Medicare Advantage plan has to. CMS sets the 2026 ceiling at $9,250 for in-network care and $13,900 if out-of-network care is mixed in, and most plans actually land well under that cap: KFF's enrollment-weighted average for 2026 works out to $5,421 in-network and $9,825 combined.
What Part C costs in 2026, on top of the Part B premium
| Cost | 2026 figure |
|---|---|
| Average extra monthly premium | $15 |
| Enrollees paying no extra premium | 75% |
| CMS maximum out-of-pocket limit, in-network | $9,250 |
| CMS maximum out-of-pocket limit, combined | $13,900 |
| Average actual out-of-pocket limit, in-network | $5,421 |
| Average actual out-of-pocket limit, combined | $9,825 |
Source: KFF, Medicare Advantage in 2026
Cost isn't the only number worth checking before your parent signs up. Medicare rates every Advantage plan from 1 to 5 stars each year, on things like screenings, how well it manages chronic conditions, and how members rate their own experience, according to AARP. It's worth looking up a plan's rating by name on Medicare's Plan Finder before your parent picks one, or re-checks the one they already have.
Switching in or out of Part C
Three windows govern this, and mixing them up is the most common mistake families make.
The Initial Enrollment Period is the first chance, seven months around your parent's 65th birthday. The yearly Open Enrollment Period, October 15 to December 7, 2026, is the one most people have heard of: your parent can join, drop or switch a Part C plan, or move between Original Medicare and Advantage entirely, with the change starting January 1. Less known is the Medicare Advantage Open Enrollment Period, January 1 to March 31, 2026, which only opens for people already in an Advantage plan. During it your parent can switch to a different Advantage plan or drop out to Original Medicare, but can't use it to join Advantage for the first time from Original Medicare.
The three Part C enrollment windows, 2026
| Window | Who it's for | When |
|---|---|---|
| Initial Enrollment Period | Everyone, around turning 65 | 3 months before to 3 months after the birthday month |
| Open Enrollment Period | Everyone | October 15 to December 7, 2026 |
| Medicare Advantage Open Enrollment Period | Only people already in an Advantage plan | January 1 to March 31, 2026 |
Source: Medicare.gov, joining a health or drug plan
There's a fourth door that doesn't run on a calendar at all. If a 5-star plan is available where your parent lives, AARP notes that a one-time switch into it is allowed at any point in the year, outside all three windows above. It's a narrow exception, but it exists for exactly the reason you'd guess: Medicare wants people able to move toward the plans it rates best, whenever that becomes possible.
If your parent is mid-decision on any of this, a SHIP counsellor is free and doesn't sell plans, which makes it a cleaner first opinion than a call from an agent. Our guide to Medicare parts explained goes further into how Part C sits next to Parts A, B and D if the bigger picture is what's missing.
Frequently asked questions
Is Medicare Part C the same thing as Medicare Advantage?
Yes. Part C is the lettered name in Medicare's own rules. Medicare Advantage is the name you'll actually see on a card or in a plan's marketing. They mean the same plan.
Does Medicare Part C replace Original Medicare?
It replaces how your parent's Part A and Part B benefits are delivered, by a private company instead of directly through Medicare, but it has to cover at least what Original Medicare covers. Parts A and B don't go away; the plan takes over paying for them.
Does Medicare Part C cost extra?
It can, but often less than people expect. KFF's 2026 figures put the average added premium at $15 a month, with three quarters of enrollees paying no extra premium beyond the standard Part B amount. Your parent still pays the Part B premium regardless of which route they choose.
Does Medicare Part C cover dental, vision or hearing?
Some plans add these as extra benefits, which Original Medicare generally doesn't cover on its own. "Some" is doing real work in that sentence: coverage varies plan to plan, so check your parent's specific plan documents rather than assume.
Can my parent switch out of a Medicare Part C plan?
Yes, during the yearly Open Enrollment Period (October 15 to December 7, 2026) or, for people already in an Advantage plan, the Medicare Advantage Open Enrollment Period (January 1 to March 31, 2026). A 5-star plan in the area can also be joined any time, through a separate one-time window.
Does having kidney failure stop someone joining a Medicare Part C plan?
No, not anymore. That restriction was removed years ago. Medicare.gov's current enrollment page lists end-stage renal disease only as a condition that can make someone eligible for Medicare earlier than 65, not as a reason to be turned away from an Advantage plan.
