What Medicare Part B Covers

What Is Medicare Part B?

Direct answer: Medicare Part B is outpatient medical insurance, covering doctor visits, preventive screenings, durable medical equipment, lab tests, mental health services, and physical therapy. While Medicare Part A covers inpatient hospital stays, Part B covers the medical care you receive without being admitted overnight. Together they form Original Medicare. Part B carries a monthly premium, an annual deductible, and standard coinsurance, with enrollment timing that directly affects whether you pay a permanent late penalty.

What Does Medicare Part B Cover?

Category: Outpatient Care

What’s Included: Doctor visits, outpatient surgeries, and medical care that does not require an overnight hospital stay.

Category: Preventive Services

What’s Included: Screenings such as mammograms and colonoscopies, recommended vaccines, and annual wellness visits.

Category: Mental Health

What’s Included: Therapy, counseling, and other behavioral health services provided by licensed mental health professionals.

Category: Durable Medical Equipment (DME)

What’s Included: Doctor-prescribed medical equipment, including wheelchairs, walkers, oxygen equipment, and similar devices.

Category: Lab Tests and Imaging

What’s Included: Diagnostic and monitoring services such as blood tests, X-rays, MRIs, and other imaging procedures.

Category: Physical Therapy

What’s Included: Rehabilitation services designed to improve mobility, restore function, and help manage pain.

Many preventive services are covered at no additional cost when they meet Medicare’s specific guidelines for frequency and medical criteria — worth confirming with your provider before scheduling, since exceeding the covered frequency can trigger out-of-pocket costs even for an otherwise-covered service.

What Does Medicare Part B Cost?

Part B costs scale with your income and generally include three components:

• Monthly premium: Most enrollees pay the standard premium; higher earners pay an income-related surcharge (IRMAA) on top of it.
• Annual deductible: The amount you pay out of pocket before Part B starts covering costs, met once per year.
• Coinsurance: After meeting the deductible, you typically pay 20% of the Medicare-approved amount for most covered services.

Budgeting around all three components — not just the premium — gives a realistic picture of your annual Part B costs.

Who Is Eligible for Medicare Part B?

• Age 65 and older: U.S. citizens or legal residents who have lived in the U.S. continuously for at least five years.
• Under 65 with a qualifying disability: Eligible after receiving Social Security Disability Insurance (SSDI) for a qualifying period.
• Specific conditions regardless of age: End-Stage Renal Disease (ESRD) or Amyotrophic Lateral Sclerosis (ALS).

If you’re already receiving Social Security benefits when you become eligible, enrollment is automatic. Otherwise, you need to actively sign up.

How Do I Enroll in Medicare Part B?

1. Confirm eligibility based on age, disability status, or a qualifying condition.
2. Enroll during the right window:
   • Initial Enrollment Period (IEP): A seven-month window centered on your 65th birthday.
   • General Enrollment Period (GEP): An annual window each winter for anyone who missed their IEP.
   • Special Enrollment Period (SEP): Available if you delayed Part B due to active employer coverage, opening once that coverage ends.
3. Apply through Social Security, online or by phone.
4. Submit required documentation promptly to avoid processing delays.

Important update if you’ve delayed enrollment before: under a change to enrollment rules, coverage through the General Enrollment Period now starts the month immediately following your enrollment, rather than being delayed for months as it once was. This is a meaningful improvement — it used to mean a potentially long gap in coverage depending on when in the window you signed up. If you’re relying on older information (including some outdated articles still circulating online), don’t assume you’ll face that old delay.

How Do I Avoid the Part B Late Enrollment Penalty?

Missing your enrollment window without qualifying for a Special Enrollment Period triggers a permanent penalty: your premium increases by roughly 10% for each full 12-month period you were eligible but didn’t enroll. This penalty applies for as long as you have Part B — it doesn’t expire or get reassessed later. Enrolling on time, or confirming you qualify for a Special Enrollment Period before delaying, is the only way to avoid it.

What Doesn’t Medicare Part B Cover?

• Routine dental care: cleanings, fillings, and checkups.
• Routine vision services: eye exams for glasses or contact lens prescriptions.
• Cosmetic procedures, unless medically necessary.
• Hearing aids: devices and routine hearing tests.
• Long-term custodial care: nursing home stays beyond medically necessary skilled nursing services.

For these gaps, many beneficiaries look to Medicare Advantage plans or supplemental insurance, since Original Medicare alone doesn’t fill them.

Bottom Line

Medicare Part B covers the outpatient and preventive backbone of your healthcare — doctor visits, screenings, DME, and more — but leaves routine dental, vision, and hearing care uncovered. Enrollment timing matters more than most people realize: missing your window triggers a permanent premium penalty, though the General Enrollment Period no longer carries the long coverage-start delay it once did. An independent Medicare broker can walk through your specific enrollment timing and coverage gaps at no cost to you.

Key Takeaways

• Medicare Part B covers outpatient care, preventive services, mental health care, durable medical equipment, lab tests, and physical therapy.
• Part B costs include a monthly premium (higher for high earners via IRMAA), an annual deductible, and standard 20% coinsurance on most services.
• Enrollment happens during your Initial Enrollment Period, the General Enrollment Period, or a Special Enrollment Period if you delayed due to employer coverage.
• The General Enrollment Period now results in coverage starting the month after you enroll — a meaningful change from the longer delay that used to apply.
• Missing your enrollment window without a Special Enrollment Period triggers a permanent premium penalty of roughly 10% per 12-month period delayed.
• Part B does not cover routine dental, vision, hearing aids, or long-term custodial care — gaps typically filled by Medicare Advantage or supplemental insurance.

FAQ – Medicare Part B Cover

What does Medicare Part B cover?
Outpatient doctor visits, preventive screenings and vaccines, mental health services, durable medical equipment, lab tests and imaging, and physical therapy.

How much does Medicare Part B cost?
A monthly premium (higher for high earners), an annual deductible, and 20% coinsurance on most covered services after the deductible is met.

Who is eligible for Medicare Part B?
People 65 and older who are U.S. citizens or long-term legal residents, people under 65 who’ve received SSDI for a qualifying period, and people with ESRD or ALS regardless of age.

When can I enroll in Medicare Part B?
During your seven-month Initial Enrollment Period around your 65th birthday, the annual General Enrollment Period if you missed your IEP, or a Special Enrollment Period if you delayed due to active employer coverage.

What happens if I enroll late?
You may face a permanent premium penalty of roughly 10% for each 12-month period you were eligible but didn’t enroll, unless you qualified for a Special Enrollment Period.

Does coverage still start in July if I use the General Enrollment Period?
No — this changed. Coverage now begins the month immediately following enrollment during the General Enrollment Period, not on a delayed fixed date as it once did.

What doesn’t Medicare Part B cover?
Routine dental care, routine vision exams and glasses, cosmetic procedures, hearing aids, and long-term custodial nursing home care.