The Short Answer
Medicare Part B is the piece of Medicare that covers outpatient medical care — doctor visits, preventive services, durable medical equipment, and many outpatient procedures. Unlike Part A, almost everyone pays a monthly premium for Part B, and that premium is often deducted directly from a Social Security check. After a yearly deductible is met, Part B typically pays 80% of the approved cost for covered services, leaving you responsible for the remaining 20% (coinsurance) unless other coverage fills that gap.
In short, Part B is medical insurance for everyday care — the counterpart to Part A’s hospital coverage.
What Part B Covers
- Doctor visits and outpatient specialist care, including office visits, whether at a clinic, doctor’s office, or hospital outpatient department.
- Preventive services, such as an annual wellness visit, many vaccines, and screenings, often covered at no additional cost when a provider accepts Medicare’s approved amount.
- Durable medical equipment, like wheelchairs, walkers, and oxygen equipment, when medically necessary.
- Outpatient services, such as lab tests, x-rays, ambulance transport, and outpatient mental health care.
How Part B Costs Work
- A monthly premium is charged to almost everyone, set each year and often higher for people with higher reported income.
- An annual deductible applies once per calendar year before Part B starts sharing costs.
- After the deductible, Part B typically pays 80% of the Medicare-approved amount for covered services, and you (or supplemental coverage) pay the remaining 20%.
- There’s no yearly out-of-pocket cap built into Original Medicare Part B alone — that 20% coinsurance can add up, which is why many people pair it with supplemental coverage.
Part A vs. Part B
- Part A — hospital insurance for inpatient stays, skilled nursing, and hospice; usually premium-free.
- Part B — medical insurance for doctor visits, outpatient care, and preventive services; almost always has a monthly premium.
A Simple Example
Example: A Medicare beneficiary sees a specialist for an outpatient procedure that Medicare approves at $500. After meeting the yearly Part B deductible earlier in the year, Part B pays 80% of the $500 ($400), and the beneficiary owes the remaining 20% ($100) as coinsurance — unless a Medigap policy or other supplemental coverage picks up that portion instead.
The Bottom Line
Medicare Part B covers the everyday medical care that Part A doesn’t — doctor visits, outpatient procedures, and preventive services — in exchange for a monthly premium and ongoing coinsurance. Because Part B alone leaves that 20% coinsurance uncapped, many people pair it with a Medigap policy or Medicare Advantage plan to limit their exposure. Together, Parts A and B make up what’s known as Original Medicare.
Frequently Asked Questions
What is Medicare Part B in simple terms?
It’s the medical insurance part of Medicare, covering doctor visits, outpatient care, and preventive services, in exchange for a monthly premium most people pay.
How much does Medicare Part B cost?
There’s a standard monthly premium set each year, plus an annual deductible. Higher-income beneficiaries pay more through an income-related adjustment. Check Medicare.gov for the current year’s figures.
Can I skip Part B if I don’t need it yet?
You can delay Part B if you have qualifying coverage elsewhere, such as through current employment. Delaying without qualifying coverage can trigger a late-enrollment penalty added to your premium for as long as you have Part B.
Does Part B cover prescription drugs?
Only certain drugs administered in a clinical setting, like some infusions or injections given by a doctor. Prescription drugs you fill at a pharmacy fall under Part D, not Part B.
Is there a cap on what I’ll pay out of pocket under Part B?
Original Medicare Part B on its own has no annual out-of-pocket maximum. That’s a major reason people add a Medigap policy or choose a Medicare Advantage plan, both of which can cap costs differently.
Is Part B premium deducted from Social Security?
For most beneficiaries already receiving Social Security, yes — the Part B premium is automatically deducted from the monthly benefit check. Others are billed directly.
This article is for educational purposes only and is not insurance, financial, tax, or legal advice. Medicare rules, costs, and coverage change over time and vary by plan and location. Visit Medicare.gov or consult a licensed insurance agent or qualified professional before making decisions about your coverage.