What is Medicare Part B?
Medicare Part B is the medical insurance component of Original Medicare. While Part A covers inpatient hospital care, Part B covers outpatient services — everything from routine doctor visits and lab tests to preventive screenings and durable medical equipment. Part B is optional, but most people enroll because the late enrollment penalty is permanent and the coverage is essential.
Unlike Part A, Part B always has a monthly premium. The standard premium in 2026 is $202.90/month, though higher-income beneficiaries pay more through IRMAA (Income-Related Monthly Adjustment Amount) surcharges.
What Medicare Part B Covers
- Doctor visits (primary care and specialists)
- Outpatient hospital services and surgery
- Preventive care (annual wellness visit, screenings, vaccines)
- Durable medical equipment (wheelchairs, walkers, CPAP machines)
- Lab tests, X-rays, and diagnostic imaging
- Mental health services (outpatient)
- Ambulance services (when medically necessary)
- Physical, occupational, and speech therapy (outpatient)
- Diabetes supplies and self-management training
- Prescription drugs (covered by Part D)
- Routine dental, vision, and hearing care
- Cosmetic surgery
- Acupuncture (except for chronic low back pain)
- Long-term custodial care
2026 Medicare Part B Costs
- $202.90
- Monthly Premium
- Standard amount; higher for high earners
- $283
- Annual Deductible
- You pay 100% of costs until this is met
- 20%
- Coinsurance
- Your share after the deductible; no cap
IRMAA: Income-Related Premium Surcharges
If your modified adjusted gross income (MAGI) exceeds certain thresholds, you pay a higher Part B premium. These surcharges are called IRMAA (Income-Related Monthly Adjustment Amount). Medicare uses your income from two years prior — so 2026 premiums are based on your 2024 tax return.
| Individual Income (2024) | Married Filing Jointly | Monthly Premium | IRMAA Surcharge |
|---|---|---|---|
| $109,000 or less | $218,000 or less | $202.90 | $0 |
| $109,001 – $137,000 | $218,001 – $274,000 | $284.10 | $81.20 |
| $137,001 – $171,000 | $274,001 – $342,000 | $405.80 | $202.90 |
| $171,001 – $205,000 | $342,001 – $410,000 | $527.50 | $324.60 |
| $205,001 – $500,000 | $410,001 – $750,000 | $649.20 | $446.30 |
| Above $500,000 | Above $750,000 | $689.90 | $487.00 |
IRMAA also applies to Part D premiums. You can appeal an IRMAA determination if your income has decreased due to a life-changing event (retirement, divorce, death of spouse).
Who Qualifies for Medicare Part B?
You're eligible for Part B if you're eligible for Part A. This includes U.S. citizens and permanent residents who are age 65 or older, or under 65 with a qualifying disability, ESRD, or ALS. Unlike Part A, Part B always has a premium — there's no premium-free version.
When to Enroll in Part B
- 1
Initial Enrollment Period (IEP)
A 7-month window: 3 months before your 65th birthday month, your birthday month, and 3 months after. Enroll early to avoid a gap in coverage.
- 2
Special Enrollment Period (SEP)
If you have employer coverage through active employment, you can delay Part B and enroll during an 8-month SEP after that coverage ends or employment ends — whichever comes first.
- 3
General Enrollment Period (GEP)
If you miss your IEP and don't qualify for a SEP, you can enroll January 1 – March 31 each year. Coverage starts July 1. A late enrollment penalty applies.
Late Enrollment Penalty
The penalty does not apply if you had creditable coverage (like employer group health insurance based on active employment) during the delay period.