If Medicare were a two-part movie, Part A is the hospital coverage and Part B is the “everything you do outside the hospital” coverage. Many people use Part B regularly, even if they never have a major hospital stay.

In 2026, the big cost mechanics for Part B still come down to five things: your monthly premium, a yearly deductible, a typical 20% share of approved costs, whether your income triggers an extra premium (IRMAA), and whether you owe a late enrollment penalty. Let’s walk through it in plain English, with simple examples so you can eyeball what you might actually pay.

A retiree sitting at a kitchen table sorting Medicare paperwork and a checkbook beside a laptop, natural window light, real-life photo

What Medicare Part B covers

Medicare Part B is medical insurance. It mainly covers care you receive from doctors and other providers, and services you get as an outpatient.

Common things Part B pays for

  • Doctor and specialist visits (primary care, cardiology, dermatology, etc.)
  • Outpatient services like same-day procedures, outpatient hospital care, and observation services
  • Lab work and diagnostic tests such as bloodwork, X-rays, MRIs, CT scans (coverage depends on medical necessity and setting)
  • Emergency room and outpatient hospital services (often billed under Part B unless you are formally admitted as an inpatient)
  • Ambulance services in medically necessary situations
  • Durable medical equipment (DME) like walkers, wheelchairs, oxygen equipment (when prescribed and from approved suppliers)
  • Mental health services such as outpatient therapy and counseling
  • Preventive services including many screenings and vaccines (often at low cost or $0 when billed correctly)

What Part B generally does not cover

This is where people get surprised. Part B usually does not pay for:

  • Routine dental care (cleanings, fillings, dentures)
  • Routine vision exams and most eyeglasses
  • Hearing aids and most hearing exams for fitting
  • Long-term custodial care (help with bathing, dressing, etc.)
  • Most care received outside the U.S.

Those gaps are a big reason people look at Medicare Advantage plans, standalone dental and vision insurance, or budgeting separately for these costs.

Part B costs in 2026

Quick note on 2026 numbers: CMS announces the standard Part B premium and the Part B deductible each year, typically in the fall for the following calendar year. If you are reading this before the official 2026 amounts are published, treat those figures as “to be announced” and focus on how the math works. Once the numbers are out, you can plug them in.

1) Your monthly premium

Most people pay a monthly Part B premium. The premium is typically deducted from your Social Security benefit (or billed directly if you are not yet drawing Social Security).

2) IRMAA: the income-related surcharge

If your income is above certain thresholds, Medicare adds an extra amount to your Part B premium called IRMAA (Income-Related Monthly Adjustment Amount). It is based on your modified adjusted gross income (MAGI) from two years prior. For example, 2026 premiums are generally based on your 2024 tax return.

If you want the full income brackets and what counts as MAGI, see our dedicated guide: Medicare IRMAA (Income-Related Monthly Adjustment Amount) Explained.

Two practical notes I always share with friends:

  • IRMAA is not permanent. If your income drops due to certain life events, you can often request a new determination.
  • Big one-time income events (selling a property, large Roth conversion, big capital gains year) can trigger IRMAA later, so planning ahead matters.

3) The annual Part B deductible

Part B has a yearly deductible. That means you generally pay out of pocket for Part B-covered services until you hit that deductible for the year.

4) Typical 20% coinsurance after the deductible

After you meet the deductible, Medicare Part B typically pays 80% of the Medicare-approved amount for covered services, and you pay the remaining 20%.

Medicare-approved amount is the rate Medicare says is reasonable for a covered service. If your provider accepts Medicare assignment, they agree to that rate.

That 20% is the piece that can sting, because there is no built-in out-of-pocket maximum in Original Medicare (Part A + Part B) by itself. A single expensive outpatient procedure can leave you with a meaningful bill.

5) The Part B late enrollment penalty (LEP)

If you delay signing up for Part B when you are first eligible and you do not have other coverage that lets you delay safely, you may be hit with a late enrollment penalty. In plain terms, Medicare can add a long-term surcharge to your Part B premium.

  • The penalty is typically 10% for each full 12-month period you could have had Part B but did not sign up.
  • In many cases, you pay that higher premium for as long as you have Part B.

The most common “safe” reason to delay Part B is having coverage from current employment (yours or a spouse’s) through a group health plan. On the other hand, COBRA and retiree coverage usually do not let you delay Part B without risking a penalty.

If you are unsure whether your current coverage lets you delay Part B safely, it is worth confirming before you miss a deadline. This is one of those “measure twice, cut once” Medicare decisions.

An older adult handing an insurance card to a receptionist at a medical clinic front desk, candid real-life photo

How Part B pays

Here is the cleanest way to think about it:

  1. You pay your monthly premium no matter what, even if you do not see a doctor.
  2. You pay the Part B deductible first (for covered services) before coinsurance kicks in.
  3. Then you usually pay 20% of the Medicare-approved amount for Part B services.
  4. If a provider does not accept assignment, your cost can be higher. In many cases, a non-participating provider can charge up to 15% more than the Medicare-approved amount (this is called the limiting charge), and you may owe that difference.

This is also why Part B is often paired with either Medigap or Medicare Advantage, which we cover below.

Two bill examples

Let’s use simple numbers to show the flow. These are examples, not official 2026 amounts.

Example 1: A routine visit early in the year

Scenario: You see your primary care doctor in January for a non-preventive visit. The Medicare-approved amount for the visit is $200.

  • If you have not met your Part B deductible yet, you may pay the full $200 (up to the remaining deductible amount).
  • After you meet the deductible, for a similar $200 visit you typically pay 20% and Medicare pays 80%.

So after the deductible is met, you would pay about $40 and Medicare would pay about $160.

Small but important: many preventive services have different cost rules and are often $0 when billed correctly. This example is intentionally a standard, non-preventive office visit.

Example 2: An outpatient procedure that costs more than you expect

Scenario: Later in the year you have an outpatient procedure with a Medicare-approved amount of $5,000, and you already met your deductible.

  • Medicare typically pays 80%: $4,000
  • You typically pay 20%: $1,000

This is the exact moment many households realize why “just 20%” can still be a big number when the bill is big.

If you are trying to budget for healthcare, the best question is not “What’s the copay?” It’s “What’s my exposure if something expensive happens under Part B?”

Part B with Medigap

If you keep Original Medicare (Part A + Part B), you can add:

  • Part D for prescription drugs, and
  • Medigap (Medicare Supplement Insurance) to help cover your out-of-pocket costs.

Medigap plans are standardized in most states (Plans G, N, etc.). In practical terms, Medigap is designed to reduce surprises by covering some or most of what you would otherwise pay under Part B, like the 20% coinsurance.

Why people like Medigap

  • Lower bill shock. Your Part B coinsurance can be greatly reduced depending on the plan.
  • Broad provider access. You can generally see any provider that accepts Medicare.
  • Simpler claims. Medicare pays first, supplement pays second in many cases.

The tradeoff is you typically pay an additional monthly premium for the Medigap policy.

One timing note: Medigap rules can vary by state, and in many situations you may face medical underwriting if you apply outside certain protected enrollment windows.

An older couple sitting on a couch reviewing medical bills and an insurance statement together in a bright living room, real-life photo

Part B with Medicare Advantage

Medicare Advantage plans bundle your Part A and Part B benefits into a private plan. Most plans also include Part D.

Key point that trips people up: you still generally pay the Part B premium even if you enroll in Medicare Advantage. The Advantage plan may charge an additional premium (some are $0), and then you pay copays or coinsurance as you use care.

Why people choose Advantage

  • Extra benefits may be included, like dental, vision, hearing, fitness, or OTC allowances.
  • Built-in out-of-pocket maximum for covered medical services, which Original Medicare does not have on its own.
  • Predictable copays for many common services (though not always cheaper overall).

Tradeoffs to watch

  • Networks and referrals may apply (HMO/PPO rules).
  • Prior authorization may be required for certain services.
  • Cost sharing varies by plan, so you want to review the Evidence of Coverage closely.

Quick checklist for 2026

  • Are you paying the standard premium or IRMAA? If you might be subject to IRMAA, read our IRMAA guide and consider whether a life event or income change applies.
  • What is the current year deductible? Plug in the official 2026 deductible once CMS publishes it.
  • Do your doctors accept Medicare assignment? This can affect what you owe, including possible limiting charges.
  • Are you protected from the 20% coinsurance? Medigap can reduce it. Medicare Advantage may cap your annual out-of-pocket spending.
  • Could you owe a late enrollment penalty? If you delayed Part B, confirm whether you had coverage from current employment through a group health plan and whether you enrolled in time.
  • Do you want an out-of-pocket maximum? That single feature is a deciding factor for many households.

Bottom line

Medicare Part B is the workhorse for everyday healthcare, covering doctor visits, outpatient care, emergency room services that are billed as outpatient, and many preventive services. In 2026, your costs will still center on a monthly premium (plus possible IRMAA), a yearly deductible, and usually 20% coinsurance after the deductible. If you enroll late without coverage from current employment that allows you to delay, the late enrollment penalty can raise your premium long-term.

If you want fewer surprise bills, your next decision is how you want to “wrap” Part B: Medigap (often smoother bills and broad provider access) or Medicare Advantage (often extra benefits and an out-of-pocket maximum, with network rules).

Friendly next step: If you tell me whether you are leaning Original Medicare or Advantage and about how often you see doctors, you can usually estimate your real-world Part B exposure in under 10 minutes.