Medicare Part B covers doctor visits and outpatient care; Medicare Part C is an alternative way to get all your Medicare benefits through a private insurance company instead of the government program.
Medicare Part B is the government's medical insurance that pays for doctor office visits, lab tests, imaging like X-rays, mental health care, and outpatient hospital services. You pay a monthly premium for Part B, and it typically starts when you turn 65 unless you delayed it.
Medicare Part C, also called Medicare Advantage, is a private insurance plan that bundles Part A (hospital) and Part B (medical) coverage into one plan. Instead of getting your benefits directly from Medicare, you get them through an insurance company that contracts with Medicare. Part C plans often include prescription drug coverage and extras like dental or vision, which Original Medicare does not.
The choice between Part B alone and Part C is not about one being "better"—it depends on your doctors, your budget, and how much medical care you use. This guide explains how each works so you can understand the real differences.
Key Takeaways
- Part B is the government program that covers doctor visits, tests, and outpatient care; you pay a monthly premium and can see any doctor who accepts Medicare.
- Part C is a private insurance alternative that bundles hospital and medical coverage, often includes prescription drugs and dental, but limits you to doctors in the plan's network.
- Part B requires you to also have Part A (hospital insurance) and to pay a deductible and coinsurance when you use services.
- Part C plans have monthly premiums, copays, and out-of-pocket limits that vary by plan and insurer.
- You can switch between Part B and Part C during the annual enrollment period each fall, or when you first turn 65.
What Medicare Part B Covers
Part B pays for doctor office visits, whether your doctor is in a hospital, clinic, or private practice. It covers preventive care like annual wellness visits and screenings at no cost to you after you meet your deductible. It also pays for lab work, imaging, physical therapy, mental health counseling, and emergency room visits.
Part B does not cover dental, vision, hearing aids, or long-term care. If you need these services, you can buy a separate plan or pay out of pocket. Part B also does not cover prescription drugs—for that, you need Part D, a separate prescription drug plan you add on top of Part B.
With Part B, you can see any doctor, specialist, or hospital in the United States that accepts Medicare. There is no network, no referral requirement, and no approval needed before you see someone. You pay a monthly premium (the amount changes each year based on your income), a yearly deductible, and then coinsurance (usually 20 percent) for most services after the deductible is met.
What Medicare Part C Covers
Part C plans must cover everything Part A and Part B cover, but they do it through a private insurance company. Most Part C plans are Health Maintenance Organizations (HMOs) or Preferred Provider Organizations (PPOs). HMOs require you to use doctors and hospitals in their network and usually require a referral to see a specialist. PPOs let you see out-of-network doctors, but you pay more.
Many Part C plans include prescription drug coverage (Part D) built in, so you do not have to buy a separate drug plan. Some plans also offer dental, vision, hearing, or fitness benefits that Original Medicare does not. These extras vary widely by plan and by region.
Part C plans have a monthly premium, copays for visits and services, and an annual out-of-pocket limit. Once you hit that limit, the plan pays 100 percent of covered services for the rest of the year. This can be helpful if you have high medical costs, because you know exactly how much you will spend.
How Part B and Part C Differ in Cost
Part B has a standard monthly premium set by Medicare each year. In 2024, the standard premium is $164.90 per month for most people, though higher earners pay more. You also pay a yearly deductible (currently $240) and then 20 percent coinsurance for most services. There is no annual out-of-pocket limit with Part B alone, so costs can add up if you have a serious illness or injury.
Part C plans have their own monthly premiums, which vary by plan and insurer. Some plans have zero premium, meaning you pay only Medicare's Part B premium. Part C plans also have copays (for example, $15 for a doctor visit, $300 for an emergency room visit) and an annual out-of-pocket limit. Once you reach that limit, the plan covers everything. The out-of-pocket limit varies by plan but is capped by Medicare at a maximum amount each year.
Part C plans often cost less per month than Part B plus a separate Part D drug plan, especially if you use a lot of prescription drugs. However, Part C networks are smaller, so you may pay more if you want to see a doctor outside the plan.
Network and Doctor Choice: Part B Versus Part C
With Part B, you have complete freedom to see any doctor, specialist, or hospital that accepts Medicare. There is no network, no approval process, and no penalty for seeing someone out of network because there is no network at all. This is valuable if you have a longtime doctor you want to keep or if you live in a rural area where Part C plans may not be available.
Part C plans restrict you to a network of doctors and hospitals. If you see someone outside the network, you usually pay the full cost yourself (except in emergencies). If you have a preferred doctor or specialist, you need to check whether they are in the Part C plan's network before you sign up. Some people find this limiting; others do not mind if their current doctors are in the plan.
Part C HMO plans typically require a referral from your primary care doctor before you can see a specialist. Part C PPO plans let you see specialists without a referral, but you pay more. Part B has no primary care doctor requirement and no referral system.
Prescription Drug Coverage: Part B and Part C
Part B does not include prescription drug coverage. If you take medications, you must buy a separate Part D plan. You can add Part D to Part B at any time, though waiting to sign up can result in a penalty if you go without coverage for more than 63 days.
Most Part C plans include prescription drug coverage as part of the plan. This means your drugs are covered under the same plan as your medical care, with one deductible and one out-of-pocket limit. Some Part C plans have zero premium and include drug coverage, which can save money if you take multiple medications.
If you choose Part B, you have more choice in which drug plan to buy—there are usually dozens of Part D plans in each region, and you can switch to a different one every year during open enrollment. With Part C, your drug coverage is tied to your medical plan, so switching drug plans means switching your entire health plan.
When You Can Switch Between Part B and Part C
You can change from Part B to Part C, or from Part C to Part B, during the Medicare Annual Enrollment Period, which runs from October 15 to December 7 each year. Changes take effect January 1 of the following year. This is the main window for switching.
If you are new to Medicare (turning 65 or becoming may be able to access), you have a seven-month Initial Enrollment Period to sign up. During this time, you can choose Part B or Part C without penalty. If you miss this window and do not sign up for Part B when you are first may be able to access, you may owe a lifetime penalty on your premium.
Part C plans also have their own disenrollment period from January 1 to February 14 each year. During this time, you can drop your Part C plan and switch to Original Medicare (Part B) without waiting for the fall enrollment period. This is useful if you are unhappy with your plan early in the year.
Frequently Asked Questions
Do I have to choose between Part B and Part C, or can I have both?
You cannot be enrolled in both Part B and Part C at the same time. You choose one or the other. If you are in Part C and want to switch to Part B, you must disenroll from Part C first. The reverse is also true.
What happens if I do not sign up for Part B when I turn 65?
If you do not sign up for Part B during your Initial Enrollment Period and you do not have other may have access to coverage, you will owe a permanent penalty on your Part B premium for as long as you have Medicare. The penalty is 10 percent of the standard premium for each full year you were may be able to access but did not sign up.
Can I use my Part B doctor if I switch to Part C?
Only if your doctor is in the Part C plan's network. Before you switch to a Part C plan, check the plan's provider directory to see whether your current doctors are included. If they are not, you will need to find new doctors or pay out of pocket to see them.
Does Part C cover everything that Part B covers?
Part C must cover all the same services as Part B, but the copays, deductibles, and out-of-pocket limits are different. Part C may also exclude certain providers or services if they are outside the network. Read the plan's coverage documents to understand what is and is not covered.
What is the difference between a Part C HMO and a Part C PPO?
HMO plans require you to use in-network doctors and usually require a referral to see a specialist. PPO plans let you see out-of-network doctors without a referral, but you pay more. PPO plans are more flexible but typically have higher premiums and copays than HMO plans.