Medicare Part C vs Part D Explained: What’s the Difference in 2027?

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Medicare’s alphabet of parts trips up a lot of people, and Part C versus Part D is one of the most common points of confusion. The short version: Part C is how you get your overall health coverage; Part D is how you get prescription drug coverage. They’re not competing options — how they relate to each other depends on which path you choose for your general coverage. Here’s the full picture, including one mistake that can quietly throw you out of your plan.

The Quick Answer

• Medicare Part C (Medicare Advantage) is an all-in-one private alternative to Original Medicare, bundling your Part A and Part B benefits — and usually your prescription drugs — into one plan
• Medicare Part D is prescription drug coverage only, either as a standalone plan added to Original Medicare or bundled inside a Part C plan
• You don’t hold both at once — and trying to has a consequence most people don’t expect, covered below

Put simply: Part C answers “how do I get my overall Medicare coverage?” and Part D answers “how do I get my prescriptions covered?” Your answer to the first decides how you answer the second.

Medicare Part C (Medicare Advantage) Explained

Part C is Medicare’s private-insurance alternative to Original Medicare. Medicare pays a private insurance company a set amount per enrollee, and the company bundles everything into one plan: all of what Original Medicare Part A covers (hospital stays, skilled nursing, hospice, some home health), all of what Part B covers (doctor visits, outpatient care, preventive services), usually Part D prescription drug coverage, and often extras Original Medicare doesn’t include at all — dental, vision, hearing, fitness.

By law, every Medicare Advantage plan must provide at least the same coverage as Original Medicare Parts A and B. What it can do differently is how you access that coverage: most use a network structure, HMO or PPO, so your choice of providers may be narrower than with Original Medicare.

Medicare Part D Explained

Part D is prescription drug coverage, offered only through private insurers approved by Medicare. You get it one of two ways: as a standalone plan sitting on top of Original Medicare, or bundled into a Medicare Advantage plan that includes drug coverage — what’s known as an MA-PD plan.

Whichever route, each plan has its own formulary: a specific list of covered drugs sorted into cost tiers. This is why the “best” Part D coverage is genuinely different for every person. It isn’t a question of which plan is good, it’s a question of what your particular medications cost on that particular list.

The mistake that drops you out of your plan

Here’s what “you can’t have both” actually means in practice, because it isn’t that the second application gets rejected.

Medicare’s booklet on understanding Medicare Advantage plans explains that joining a separate Medicare drug plan is what disenrolls you from a Medicare Advantage plan — it happens automatically, with no need to contact the plan. That mechanism is useful when leaving Medicare Advantage is what you wanted. It is a nasty surprise when it isn’t.

So if you’re in an MA-PD plan and you sign up for a standalone Part D plan — perhaps because you found better pricing on one of your medications — you don’t end up with better drug coverage alongside your existing plan. You end up out of your Medicare Advantage plan entirely, back on Original Medicare, with no out-of-pocket maximum and none of the extras you had. Check whether your plan already includes drug coverage before applying for anything separate.

The opposite trap: plans with no drug coverage at all

The mistake above is about having too much. The less-known one is having too little. For 2027 there are 357 ordinary Medicare Advantage plans that include no drug coverage, and they are not rare oddities: in our count of the CMS plan file they are sold in 2,975 of the country’s 3,131 counties, with a median of six such plans per county. Almost all of them, 92.7%, charge a $0 plan premium, which is exactly why they catch people’s eye.

The catch is that 352 of the 357 are HMOs or PPOs, and Medicare’s own HMO and PPO pages say that if you join one without drug coverage, you can’t join a separate Medicare drug plan. Only the handful of Private Fee-for-Service and Medical Savings Account plans in the file allow a stand-alone Part D plan alongside them. So with most of these plans, choosing it means choosing to have no Medicare drug coverage for the year.

That can be a sound choice for people who already get their prescriptions somewhere else. It shows in the names: 170 of the 357 are marketed by name to veterans, such as AARP’s “Patriot No Rx” plans and Humana’s “USAA Honor” plans, built for people who fill their prescriptions through the VA. For anyone without other creditable drug coverage, it’s a costly shortcut: every month without it adds to the Part D late enrollment penalty you will pay for as long as you have drug coverage afterward.

Side-by-Side Comparison

	Part C (Medicare Advantage)	Part D (Prescription Drugs)
What it covers	Hospital + medical + (usually) drugs + extras	Prescription drugs only
Replaces Original Medicare?	Yes	No — adds to Original Medicare, or sits inside Part C
Who offers it	Private insurers	Private insurers
Can you have both separately?	Not if the Part C plan already includes drugs — joining a standalone plan disenrolls you from it
Network restrictions	Usually yes (HMO/PPO)	No provider network, but pharmacy networks apply

What Both Paths Cost: 2026, and What Changes for 2027

Cost	2026	2027	Applies to
Part B premium	$202.90/month for most people	Not yet announced	Everyone, whichever path you take
Average stand-alone Part D premium	$35.09/month	$36/month (projected)	Original Medicare + stand-alone Part D
Average Part D premium inside Medicare Advantage	$11.32/month	$7/month	Part C plans with drug coverage
Maximum Part D annual deductible	$615	$700	Both paths
Annual cap on covered drug costs	$2,100	$2,400	Both paths, identical protection
Average Medicare Advantage plan premium	$14.37/month	$12.00/month	Part C — and never replaces the Part B premium

One number that gets misquoted constantly

You will often see “$38.99” cited as the 2026 Part D premium. It isn’t what you pay. $38.99 is the national base beneficiary premium, a reference figure Medicare uses to calculate the late enrollment penalty — 1% of it per month you went uncovered. For 2027 that reference figure rises to $41.33, so anyone already paying a penalty will see it grow a little in January even if nothing else changes. The premium an actual plan charges you is a different number, and on average it is lower.

A rough monthly total for someone on Original Medicare plus a standalone Part D plan came to around $238 in 2026 before any Medigap premium: the $202.90 Part B premium plus the $35.09 average stand-alone Part D premium. Someone on Medicare Advantage pays the same $202.90 plus whatever their plan charges, which for many plans is nothing. That gap is real, but it’s only half the comparison — what it leaves out is what each path costs you when you actually use care, and for drug coverage the 2027 plan file shows that this is exactly where costs moved.

What the 2027 Plan File Shows About Drug Coverage Inside Medicare Advantage

Every year Medicare publishes a Landscape file listing every plan on sale for the coming year, with its premium, its drug deductible and how much of the premium is for the drug part. We counted the ordinary Medicare Advantage plans with drug coverage (MA-PD plans open to anyone, leaving out Special Needs Plans) in the 2026 file and in the 2027 file, the same way, and put the two side by side.

Ordinary MA-PD plans	2026	2027
Number of plans	3,351	3,196
Plans with a $0 drug deductible	16.1%	10.5%
Median drug deductible	$440	$650
Plans charging the maximum deductible	32.8% (at $615)	36.0% (at $700)
Plans whose Part D portion of the premium is $0	69.7%	71.7%
Average Part D portion of the premium, per plan	$13.22	$13.54
Plans with both a $0 deductible and a $0 Part D premium	11.4%	7.8%
Medicare Advantage plans with no drug coverage	402	357

Our own count from the CMS Landscape files for 2026 and 2027. Plan counts are plans on sale, not people enrolled.

The premium held still; the deductible did not

Read the table from top to bottom and one pattern stands out. The share of plans charging nothing for the drug part of the premium went up slightly, from 69.7% to 71.7%. But the share with no drug deductible fell by about a third, from 16.1% to 10.5%, and the typical deductible jumped from $440 to $650. More than a third of plans now sit right at the new $700 ceiling. The plans that offered the best of both — no drug premium and no drug deductible — went from roughly one in nine to roughly one in thirteen.

In plain terms, for 2027 insurers kept the monthly price looking the same and moved cost into the first months of the year, when you pay for your prescriptions yourself until the deductible is met. If you fill a few prescriptions every January, that matters more to you than a few dollars on the premium.

There is one softening factor we could measure for 2026 but not yet for 2027. In the 2026 file, 83.0% of ordinary MA-PD plans exempted at least one drug tier from the deductible, usually the cheapest generics, so many people never paid the full deductible on their routine pills. The 2027 Landscape file does not include that column, so you need to check it plan by plan in the Medicare Plan Finder.

Why our average differs from Medicare’s $7

CMS says the average Part D premium inside Medicare Advantage falls from $11.32 to $7 in 2027. Our per-plan average stays around $13.50. Both are right, because they measure different things. CMS weights its average by how many people are in each plan, and most people are in large, low-premium plans. Our figure gives every plan on the menu the same weight. Put together, they say that the plans where most people already are got cheaper, while the menu as a whole did not — so a $7 average is no promise about the plan you are looking at.

Three things to check on any MA-PD plan for 2027

1. The drug deductible, not just the premium. Anything from $0 to $700. Add it to twelve months of premium to see your real starting cost.
2. Which tiers skip the deductible. If your regular medications are cheap generics on an exempt tier, a high deductible may barely touch you.
3. Whether your drugs are on the formulary at all. The $2,400 cap only counts covered drugs. A drug the plan doesn’t list doesn’t count toward it.

Which Path Should You Choose?

This isn’t really a Part C versus Part D decision at all. It’s a decision about how you want to receive your overall coverage, and the drug question follows from it.

Choose Medicare Advantage and Part D almost always comes bundled in: one card, one premium, one network, one formulary to check. Choose Original Medicare and you have to add a standalone Part D plan yourself, because Original Medicare doesn’t cover most outpatient prescriptions — and forgetting that step is how people end up with a late enrollment penalty attached to their premium for good.

Our full Medicare Advantage vs Medicare Supplement guide works through the underlying choice properly, since that’s the decision driving everything on this page.

Frequently Asked Questions

What happens if I join a standalone Part D plan while I’m in a Medicare Advantage plan? You’ll generally be disenrolled from the Medicare Advantage plan. Joining a separate drug plan is the action that ends Medicare Advantage coverage, automatically. If you were happy with your plan and just wanted different drug coverage, that is not the outcome you were after.

Is Part D mandatory? No, but if you don’t enroll when first eligible and don’t have other creditable drug coverage, a late enrollment penalty is added to your premium when you do sign up, and it doesn’t come off again.

Does Part C automatically include Part D? Most Medicare Advantage plans do — those are MA-PD plans — but not all of them. In the 2027 plan file, 3,196 of the 3,553 plans open to anyone include drug coverage and 357 do not. Confirm it for the specific plan rather than assuming, because the answer changes what you need to do next.

Can I add a standalone drug plan to a Medicare Advantage plan that has no drug coverage? Not if it’s an HMO or a PPO, which is 352 of the 357 such plans for 2027. Medicare’s own guidance says that if you join an HMO or PPO without drug coverage, you can’t join a separate Medicare drug plan. To get drug coverage you would have to move to a plan that includes it, during an enrollment window.

Does the drug cost cap apply either way? Yes. Whether your drug coverage is a standalone Part D plan or bundled into Medicare Advantage, the same annual cap on covered drug costs applies: $2,100 in 2026 and $2,400 in 2027. Every one of the 5,165 plans with drug coverage in the 2027 file lists the same $2,400 threshold. Once you reach it, you pay nothing more for covered drugs for the rest of the year.

Which is cheaper? It depends on your medications and how much care you use, and the monthly premium is the least informative part of the answer. Medicare Advantage usually wins on premium; Original Medicare with Part D and a Medigap policy usually wins on predictability and provider access.

Bottom Line

Part C and Part D aren’t rivals. They answer different questions, and the first answer determines the second: Part C decides how you receive your overall Medicare coverage, and that decides whether your drug coverage arrives bundled or has to be added separately.

The practical thing to carry away is the interaction between them. Signing up for a standalone Part D plan while you’re in a Medicare Advantage plan doesn’t give you two kinds of drug coverage — it takes you out of Medicare Advantage. Know which kind of plan you’re in before you apply for anything.

Compare your specific options — with your own medications and doctors factored in — using the official Medicare Plan Finder (our step-by-step guide to the Plan Finder walks through every screen), or speak with your local State Health Insurance Assistance Program (SHIP) for free, unbiased guidance.

Sources

• CY2026 and CY2027 Landscape files — Centers for Medicare & Medicaid Services. Source for every plan count on this page (our own count): the 3,553 plans open to anyone in 2027, the 357 without drug coverage and where they are sold, the deductibles and Part D premium portions in both years, and the $700 maximum deductible and $2,400 out-of-pocket threshold listed for 2027.
• Medicare Advantage and Medicare Prescription Drug Programs Expected to Remain Stable in 2027 — Centers for Medicare & Medicaid Services, September 28, 2026. Source for the average stand-alone Part D premium ($35.09 in 2026, $36 projected for 2027), the average Part D premium inside Medicare Advantage ($11.32 to $7) and the average Medicare Advantage premium ($14.37 to $12.00).
• 2026 Medicare Parts A & B Premiums and Deductibles — Centers for Medicare & Medicaid Services. Source for the $202.90 standard Part B premium.
• 2026 Medicare Part D Bid Information — Centers for Medicare & Medicaid Services. Source for the $38.99 national base beneficiary premium for 2026.
• Medicare Part D 2027 National Average Monthly Bid Amount Information — Centers for Medicare & Medicaid Services, July 28, 2026. Source for the $41.33 national base beneficiary premium for 2027.
• Final CY 2026 Part D Redesign Program Instructions — Centers for Medicare & Medicaid Services. Source for the $615 maximum Part D deductible and the $2,100 annual out-of-pocket cap in 2026.
• Understanding Medicare Advantage Plans — Medicare.gov. Source for joining a separate Medicare drug plan automatically disenrolling you from a Medicare Advantage plan.
• Health Maintenance Organizations (HMOs) and Preferred Provider Organizations (PPOs) — Medicare.gov. Source for the rule that if you join an HMO or PPO without drug coverage, you can’t join a separate Medicare drug plan.

Figures on this page were checked against the sources above on October 17, 2026. The 2026 and 2027 plan counts are our own, from the two CMS Landscape files, counted the same way on the same day.

Disclaimer: Costs and figures mentioned in this article reflect 2026 and 2027 data from the Centers for Medicare & Medicaid Services (CMS) and are subject to change. Always confirm current details directly with Medicare.gov, 1-800-MEDICARE, or a licensed agent before making a decision.