Medicare Part B · Medical Insurance
Plain English. Five calm steps. No pressure.
Part B is the doctor-and-outpatient half of Original Medicare. Unlike Part A, nearly everyone pays a monthly premium — and signing up late can cost you for life. Here's how to get the timing right.
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Your Part B Path
Read them in order, or jump straight to what you need.
Know what Part B pays for — and what it doesn't.
Your 2026 premium, deductible and income brackets.
Sign up now, or safely delay? Find your answer.
Three easy ways, plus the forms for people leaving a job.
How the late penalty works, and what to do next.
Step 1 What It Covers
Part B = Medical Insurance
If Part A is for when you're admitted to the hospital, Part B is for nearly everything else — the everyday care that keeps you healthy and out of the hospital.
Office visits with your primary doctor and specialists, including care you get while in the hospital.
Lab work, X-rays, outpatient surgery, emergency room visits, and hospital observation stays.
Flu shots, many cancer screenings, and a yearly wellness visit — many at no cost to you.
Many are $0Durable medical equipment like walkers and oxygen, ambulance rides, and outpatient mental health care.
What Part B does not cover: most prescriptions you fill at a pharmacy (that's Part D), routine dental care, eye exams for glasses, hearing aids, and long-term custodial care.
The 20% has no ceiling. Original Medicare has no yearly out-of-pocket maximum. If a treatment costs $100,000, your 20% share is $20,000. That's the main reason people add a Medigap policy or choose a Medicare Advantage plan.
Step 2 What It Costs
Your 2026 Part B Costs
Part B has three costs to know. If you get Social Security, your premium is taken out of your monthly check automatically. Otherwise, Medicare sends you a bill.
If your income was above a certain level two years ago, you pay an extra amount called IRMAA (Income-Related Monthly Adjustment Amount). For 2026, Social Security looks at your 2024 tax return.
| Filed individually | Filed jointly | You pay |
|---|---|---|
| $109,000 or less | $218,000 or less | $202.90 |
| $109,001 – $137,000 | $218,001 – $274,000 | $284.10 |
| $137,001 – $171,000 | $274,001 – $342,000 | $405.80 |
| $171,001 – $205,000 | $342,001 – $410,000 | $527.50 |
| $205,001 – $499,999 | $410,001 – $749,999 | $649.20 |
| $500,000 or more | $750,000 or more | $689.90 |
Married and filing separately? Different brackets apply. Source: CMS and the Social Security Administration, 2026 amounts.
Income dropped since 2024? If you retired, stopped working, or had another life-changing event, you can ask Social Security to lower your IRMAA using form SSA-44.
On a limited income? Medicare Savings Programs, run by your state, can help pay your Part B premium — and sometimes your deductible and coinsurance too. Contact your state Medicaid office to see if you qualify.
Step 3 When to Enroll
Your Initial Enrollment Period
Your first chance to sign up is the same 7-month window as Part A, built around your 65th birthday. Sign up in the 3 months before your birthday month, and coverage starts on the first day of your birthday month.
Because Part B has a premium, some people choose to delay it. Whether that's safe depends on what other coverage you have.
You'll be enrolled in Parts A and B automatically. Your card arrives about 3 months before you turn 65. If you have job-based coverage and want to delay Part B, follow the card's instructions to decline it.
Automatic — watch your mailIf you (or your spouse) are still working and covered by that employer's group plan, you can usually delay Part B with no penalty. You'll get an 8-month Special Enrollment Period after the job or coverage ends — whichever comes first.
Usually safe to delayThese don't count as coverage from current work. Delaying Part B because you have them can lead to a lifelong penalty and a gap in coverage. Most people in this situation should sign up on time.
Don't delayThe General Enrollment Period runs January 1 – March 31 each year. Coverage starts the month after you sign up, and a late penalty may apply.
Jan 1 – Mar 31Small employer? If your employer has fewer than 20 employees, Medicare usually pays first — and your job plan may not pay much without Part B. Ask your benefits office how their plan works with Medicare before you decide to delay.
Step 4 How to Sign Up
You Enroll Through Social Security
Like Part A, Part B comes from the federal government, so you sign up with Social Security — not with an insurance company or an agent. Most people apply for Parts A and B at the same time.
Takes about 10 minutes. You don't need to start retirement benefits to apply for Medicare.
Call Social Security Monday–Friday, 8 a.m. to 7 p.m. local time. Mornings and later in the week are usually less busy.
1-800-772-1213
TTY 1-800-325-0778
Visit your local Social Security office. Calling ahead for an appointment can save you a long wait.
Leaving a job after 65? You'll need two forms:
Your application for Part B enrollment. You fill this out yourself.
Your employer completes this to show you had job-based coverage. It proves you qualify for the Special Enrollment Period.
Tip: ask HR for the CMS-L564 a month or two before your coverage ends, and pick a Part B start date that matches the day your job coverage stops — so there's no gap. Railroad workers apply through the Railroad Retirement Board at 1-877-772-5772.
Medicare will never call you to ask for your Medicare or Social Security number.
Step 5 Avoid the Penalty
The Part B Late Enrollment Penalty
If you don't sign up when you're first eligible — and you didn't have coverage from a current job — your premium goes up 10% for each full 12 months you went without Part B. And in most cases, you pay that penalty for as long as you have Part B.
Estimate only, using the 2026 standard premium of $202.90. The penalty is figured on each year's standard premium, so the dollar amount changes yearly. Social Security makes the final decision.
One more window to know: your 6-month Medigap Open Enrollment Period starts the month you're 65 or older and have Part B. During it, you can buy any Medigap policy sold in your state without health questions. Your Part B start date sets this clock — so choose it with care.
With Parts A and B in place, you choose how to fill the gaps — the 20% with no cap, and prescriptions. Learn about each path, then decide for yourself.
Hospital insurance — premium-free for most people. Read the Part A guide →
Keep Original Medicare, add a Medicare Supplement to help with your 20%, plus a separate drug plan.
A private plan that bundles Parts A and B (and usually D), with a yearly out-of-pocket maximum and a provider network.
Learn first. Compare when you're ready. Enroll yourself.
Common Questions
The standard premium is $202.90 a month, the yearly deductible is $283, and after that you generally pay 20% of the Medicare-approved amount for covered services. People with higher incomes pay more — from $284.10 up to $689.90 a month — based on their 2024 tax return.
If you already get Social Security or Railroad Retirement benefits at least 4 months before you turn 65, yes — you'll be enrolled in Parts A and B automatically. If you're not collecting benefits yet, you'll need to sign up yourself through Social Security.
Usually, if you're covered by a group health plan from your own or your spouse's current job. You'll then have 8 months after the job or coverage ends to sign up without a penalty. COBRA and retiree coverage don't count. If your employer has fewer than 20 employees, check with your benefits office first.
Your monthly premium goes up 10% for each full 12-month period you could have had Part B but didn't, unless you had coverage from current work. In most cases you pay the penalty for as long as you have Part B.
No — Part B enrollment happens only through Social Security (or the Railroad Retirement Board). Once you have Parts A and B, this site can help you learn about and compare Medicare Advantage, Medigap and Part D plans, and enroll yourself when you're ready.
Yes. To join a Medicare Advantage plan or buy a Medigap policy, you must be enrolled in both Part A and Part B — and you keep paying your Part B premium.
Still have a question? Just ask.
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Education First. Enrollment Second.