Medicare Part B is the medical insurance half of Original Medicare. It pays for doctor visits, outpatient care, lab tests, preventive screenings and medical equipment. In 2026 the standard Part B premium is $202.90 a month and the yearly deductible is $283. After that, you usually pay 20% of the Medicare-approved amount for each covered service.
If you are still sorting out how the program fits together, our guide to what Medicare is and how its parts work covers Parts A, C and D. This article stays with Part B: what it costs, what it covers, and how to avoid the penalty that follows some people for life.
What Part B covers
Part A covers inpatient stays in a hospital or skilled nursing facility. Part B picks up most of the care you get outside a hospital bed. It also pays for doctors’ services while you are in the hospital, which surprises many people.
Covered services fall into two broad groups. The first is medically necessary care, meaning services you need to diagnose or treat a condition. The second is preventive care, which aims to catch problems early or stop them from starting.
- Doctor and specialist visits, in an office or in the hospital
- Outpatient hospital care, such as emergency room visits and same-day surgery
- Clinical lab tests and most diagnostic imaging
- Durable medical equipment, for example walkers, wheelchairs and home oxygen
- Ambulance rides when other transport would endanger your health
- Outpatient mental health care, including a yearly depression screening
- Many preventive services, such as flu shots, cancer screenings and a yearly wellness visit
- Some drugs given in a clinic, like infusions and certain injections
Part B does not cover everything. Routine dental care, eye exams for glasses, hearing aids and long-term custodial care are generally left out. Most prescription drugs you pick up at a pharmacy also fall outside Part B, because those belong to Part D. The official list lives on Medicare’s coverage lookup tool, where you can search a specific test or item.
What Medicare Part B costs in 2026
CMS sets Part B amounts each fall for the coming year. The 2026 figures were published in November 2025 in the agency’s official premium and deductible fact sheet. The premium rose $17.90 from 2025, while the deductible went up $26.
| Part B cost | 2025 | 2026 |
|---|---|---|
| Standard monthly premium | $185.00 | $202.90 |
| Annual deductible | $257 | $283 |
| Coinsurance after deductible | Usually 20% | Usually 20% |
| Out-of-pocket cap | None | None |
The last row matters most. Original Medicare has no yearly limit on what you pay. So a long course of outpatient treatment can add up fast, since 20% of a large bill is still a large bill. That is why many people add a Medigap policy or choose a Medicare Advantage plan, which does have a cap.
Some services cost nothing extra. Clinical lab tests are usually $0, and many preventive services are free if your provider accepts assignment. Accepting assignment means the provider agrees to take the Medicare-approved amount as full payment. If a provider does not accept it, they can charge more, and you may pay the difference.
Higher premiums for higher incomes
Most people pay the standard $202.90. However, people with higher incomes pay an extra amount called IRMAA, short for income-related monthly adjustment amount. Social Security uses the tax return from two years earlier, so 2026 premiums are based on 2024 income.
| 2024 income, single filer | 2024 income, joint filers | 2026 monthly premium |
|---|---|---|
| $109,000 or less | $218,000 or less | $202.90 |
| $109,001 to $137,000 | $218,001 to $274,000 | $284.10 |
| $137,001 to $171,000 | $274,001 to $342,000 | $405.80 |
| $171,001 to $205,000 | $342,001 to $410,000 | $527.50 |
| $205,001 to under $500,000 | $410,001 to under $750,000 | $649.20 |
| $500,000 or more | $750,000 or more | $689.90 |
Income here means modified adjusted gross income. If your income dropped because of retirement, divorce or a spouse’s death, you can ask Social Security to use a newer year. In practice, that request often lowers the bill for people who stopped working recently.
When to sign up
Timing is the part of Part B that trips people up. Your Initial Enrollment Period lasts about seven months. It starts three months before the month you turn 65 and ends three months after it. If you already get Social Security benefits, you are usually enrolled automatically.
Still working at 65 with health coverage from your own or your spouse’s current job? Then you can often delay Part B without penalty. Once that job or the coverage ends, you get an 8-month Special Enrollment Period. Medicare’s sign-up timing page explains the rules. The clock starts when the work ends, even if you pick up COBRA. COBRA coverage does not count as current job coverage for this purpose.
If you miss both windows, the General Enrollment Period runs from January 1 to March 31 each year. Coverage then starts the month after you sign up. Even so, the late penalty can apply.
The Part B late enrollment penalty
The penalty adds 10% to your premium for each full 12-month period you could have had Part B but did not. It usually lasts as long as you have Part B, which for most people means the rest of their life.
Medicare’s own example: wait 24 months without a valid reason, and you owe a 20% penalty. For 2026, that adds $40.58 to the $202.90 premium, for about $243.50 a month. Because the penalty is a percentage, it also grows every time the standard premium rises.
You generally avoid it if you qualify for a Special Enrollment Period. People who enroll in a Medicare Savings Program usually escape it too. Details are on Medicare’s penalty page.
Help paying for Part B
If your income and savings are limited, your state may pay some or all of your Part B costs. These Medicare Savings Programs are run by state Medicaid offices. The most generous level covers the premium, the deductible and the 20% coinsurance.
Some people qualify for both Medicare and full Medicaid. In that case Medicaid usually picks up Part B costs and fills many gaps. Our explainer on Medicare vs Medicaid walks through who gets which program and how they work together.
Also check how your premium gets paid. Most people have it taken out of their Social Security check. If you do not get benefits yet, Medicare sends a bill, usually every three months. You can see more of our health explainers in the health and sports guides.
What to recheck each year
Part B numbers change every January. CMS normally announces the next year’s premium and deductible in November. As of late October 2026, the 2027 amounts have not been released. Watch for them before you budget for next year, since the premium has risen in most recent years.
This guide is general information, not medical or financial advice. Check with your doctor or with Medicare directly at 1-800-633-4227 about your own situation.
Frequently asked questions
What is Medicare Part B in simple terms?
It is the medical insurance part of Original Medicare. It covers doctors, outpatient care, lab work, preventive care and medical equipment, while Part A covers hospital stays.
How much does Medicare Part B cost per month in 2026?
The standard premium is $202.90 a month. Higher earners pay between $284.10 and $689.90, based on income from two years earlier.
Is Medicare Part B mandatory?
No. You can turn it down. But if you delay without other job-based coverage, you may owe a late penalty for as long as you have Part B.
Does Part B cover prescription drugs?
Only some. It covers certain drugs given in a doctor’s office or clinic, such as infusions. Most pharmacy prescriptions fall under Part D instead.
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