Medicare Part B costs you a monthly premium, an annual deductible, and a share of each doctor visit or service

The monthly premium for Medicare Part B in 2024 is $164.90 for most people, though some pay more based on their income. On top of that, you pay a $240 annual deductible before Medicare starts to cover outpatient services. After you meet the deductible, you typically pay 20 percent of the cost for doctor visits, lab tests, imaging, and other outpatient care — Medicare pays the other 80 percent. These amounts change each year, usually in January.

The exact premium you pay depends on your modified adjusted gross income (MAGI) from two years prior. If your income is above a certain threshold, you pay a higher premium through a system called Income-Related Monthly Adjustment Amount (IRMAA). The income brackets and thresholds change annually, so someone who paid the standard premium last year might pay more this year if their income crossed a threshold.

Key Takeaways

  • The standard Part B premium for 2024 is $164.90 per month, but you may pay more if your income is above $97,000 (single) or $194,000 (married filing jointly).
  • You pay a $240 annual deductible, then 20 percent coinsurance for most outpatient services after that.
  • Part B premiums and deductibles increase most years, usually announced in the fall for the following year.
  • If you delay enrolling in Part B when you first become may be able to access, you may face a permanent penalty of 10 percent per year of delay.

How the standard Part B premium is set each year

The Centers for Medicare & Medicaid Services (CMS) announces the new Part B premium, deductible, and coinsurance amounts in the fall, effective January 1 of the following year. The premium is calculated to cover about 25 percent of the average cost of Part B services; the federal government funds the remaining 75 percent through general tax revenue.

Because medical costs rise, the premium usually increases year to year. For example, the 2024 premium of $164.90 was higher than 2023's $164.90 (which remained flat). The exact increase depends on how much Part B services cost nationally and how many people are enrolled. You can find the current year's amounts on Medicare.gov or by calling 1-800-MEDICARE.

Income-based premiums (IRMAA) and who pays more

If your income is above a certain level, you pay a higher Part B premium through IRMAA. For 2024, single filers with MAGI above $97,000 and married couples filing jointly with MAGI above $194,000 enter the higher-income brackets. The more your income exceeds the threshold, the more you pay — the highest earners can pay up to four times the standard premium.

IRMAA uses your tax return from two years before the current year. So your 2024 premium is based on your 2022 income. If you had a major life change — retirement, loss of a spouse, or a one-time event like selling a home — you can request a recalculation by filing a Medicare Income-Related Monthly Adjustment Amount Life-Changing Event form with Social Security. This is one of the few ways to lower an IRMAA premium mid-year.

The income brackets and premium amounts shift each year. Social Security publishes the new brackets in October for the following year, so you can see whether your income will push you into a higher tier.

What Part B actually covers and what you pay

Part B covers doctor visits, outpatient hospital services, diagnostic tests, mental health care, and certain preventive services. Once you meet your $240 annual deductible, you pay 20 percent coinsurance for most services; Medicare covers 80 percent. For some preventive services — like annual wellness visits, cancer screenings, and vaccinations — you pay nothing after you meet the deductible.

The 20 percent coinsurance can add up quickly for expensive services. An MRI might cost $1,000; you would pay $200 after the deductible. A specialist visit might be $150; you pay $30. If you have a Medigap or Medicare Advantage plan, that plan may cover some or all of your coinsurance, but Part B itself does not.

Enrollment important date and late-enrollment penalties

You become may be able to access for Medicare at 65. If you do not enroll in Part B when you first become may be able to access, you pay a permanent penalty of 10 percent per year of delay for as long as you have Part B. For example, if you delay three years, your premium increases by 30 percent forever — even after you finally enroll.

The main exception is if you have employer health insurance when you turn 65. If your employer has 20 or more employees, you can delay Part B without penalty as long as you are covered by that plan. Once you leave the job or lose the coverage, you have eight months to enroll in Part B without penalty. After that window closes, the 10 percent annual penalty applies.

How to pay your Part B premium

Most people pay their Part B premium by having it deducted automatically from their Social Security check each month. If you do not receive Social Security, or if you want to pay a different way, you can pay by mail, phone, or online through your Medicare account at Medicare.gov.

If you have a Medigap or Medicare Advantage plan, you still pay your Part B premium to Medicare — your supplemental plan does not cover it. Some people on low income may receive help paying Part B premiums through the may have access to Individual (QI) program, which is run by your state. You can ask your state Medicaid office whether you may have access to.

Part B costs compared to Medicare Advantage plans

Original Medicare (Part A and Part B) has no network — you can see any doctor who accepts Medicare. You pay the standard Part B premium plus coinsurance for each service. A Medicare Advantage plan (Part C) is an alternative that bundles Part A, Part B, and prescription drug coverage into one plan run by a private insurer. Advantage plans often have lower or zero premiums, but they use networks and may have higher out-of-pocket limits.

Some people find Advantage plans cheaper if they use few services; others find Original Medicare cheaper if they see many specialists or travel frequently. The choice depends on your health, your doctors, and your budget. You can compare plans side by side on Medicare.gov during the annual enrollment period (October 15 to December 7).

Frequently Asked Questions

Does Part B cover my doctor's full bill?

No. Part B covers 80 percent of the Medicare-approved amount after you meet your deductible. Your doctor may bill you for the remaining 20 percent, or they may accept Medicare's payment as full payment. Some doctors charge more than Medicare allows; you are responsible for the difference unless they accept assignment.

What happens if I miss the Part B enrollment important date?

You can still enroll later, but you will pay a 10 percent penalty on your premium for each year you delayed. The penalty is permanent. The only way to avoid it is to have had employer coverage when you turned 65 and to enroll within eight months of losing that coverage.

Can my Part B premium go down?

The standard premium rarely goes down — it usually stays flat or increases. If you are paying an IRMAA surcharge because of high income, your premium can go down if your income drops below the threshold. You must report the income change to Social Security to request a recalculation.

Do I pay Part B costs if I have a Medigap plan?

You still pay the Part B premium to Medicare. A Medigap plan covers some or all of your coinsurance and deductible, depending on which plan you choose. Medigap does not cover the premium itself.

Is Part B mandatory?

Part B is not mandatory, but delaying enrollment without may have access to coverage results in a permanent penalty. Most people enroll at 65 to avoid the penalty, even if they do not use many services.