Medical Insurance
Medicare Part B
Medicare Part B is your outpatient medical insurance — it covers doctor visits, preventive care, lab tests, imaging, and durable medical equipment.
Part B pays 80% of approved costs after your deductible. Without supplemental coverage, you are responsible for the remaining 20% with no out-of-pocket maximum. A local specialist can help you close that gap — at no cost to you.
$185
Standard Monthly Premium
2025 standard Part B premium. Higher-income enrollees pay an IRMAA surcharge on top of the standard rate.
What Medicare Part B Covers
Medicare Part B covers two broad categories of services: medically necessary services and preventive services.
Medically necessary services are those your doctor orders to diagnose or treat a health condition — office visits, specialist consultations, lab work, X-rays, MRIs, outpatient surgery, physical therapy, mental health counseling, and durable medical equipment such as wheelchairs and walkers.
Preventive services include annual wellness visits, cancer screenings (mammograms, colonoscopies, PSA tests), diabetes screenings, cardiovascular screenings, flu and pneumonia shots, and the Initial Preventive Physical Exam ("Welcome to Medicare" visit). Many preventive services are covered at 100% with no cost-sharing when provided by a Medicare-participating provider.
Part B does not cover most inpatient hospital care (that is Part A), self-administered prescription drugs (that is Part D), routine dental, vision, or hearing care, or long-term custodial care.
2025 Medicare Part B Costs
Standard Premium
$185.00/month for most enrollees in 2025. Deducted automatically from your Social Security benefit if you are receiving it. Higher earners pay more via IRMAA.
Annual Deductible
$257 in 2025. You pay 100% of covered costs until you meet this deductible each calendar year. After that, the 80/20 cost-sharing applies.
20% Coinsurance
After your deductible, Medicare pays 80% of the Medicare-approved amount. You pay the remaining 20% with no out-of-pocket cap — this is the primary gap Medigap plans fill.
IRMAA Tier 1
Individual income $106,001–$133,000 (2023 MAGI): additional $74.00/mo surcharge. Total premium: $259.00/mo in 2025.
IRMAA Tier 2
Individual income $133,001–$167,000: additional $185.00/mo. Total: $370.00/mo. IRMAA is based on income from two years prior.
IRMAA Tier 3–5
Individual income $167,001–$500,000+: surcharges range from $296.00/mo to $443.90/mo above the standard premium. Use Form SSA-44 to appeal if income has dropped.
Late Enrollment Penalty
The Medicare Part B late enrollment penalty is permanent. If you delay enrolling in Part B without qualifying creditable coverage, your monthly premium increases by 10% for each full 12-month period you were eligible but did not enroll.
Example: If you wait 2 years past your Initial Enrollment Period without creditable coverage, your Part B premium increases by 20% — permanently. On a $185 base premium, that is an extra $37/month for life.
Creditable coverage for avoiding the penalty means active employer coverage at a company with 20 or more employees (your own or a spouse's). Retiree plans, COBRA, and individual marketplace plans do not protect you from the penalty. When you or your spouse leave active employment, you have an 8-month Special Enrollment Period to sign up for Part B without penalty.
Part B and Your Supplemental Coverage Options
Medicare Advantage (Part C)
Medicare Advantage plans bundle Part A, Part B, and usually Part D into a single plan through a private insurer. They replace Original Medicare for most services and often include extra benefits (dental, vision, hearing). You still pay the Part B premium plus any plan premium. Advantage plans use networks and prior authorization requirements.
Learn about Medicare Advantage →Medicare Supplement (Medigap)
Medigap plans fill the gaps in Original Medicare — including the Part B 20% coinsurance and deductible. Plan G is the most comprehensive option available to new enrollees today (Plan F is closed to those new to Medicare after 2020). Medigap plans work with any Medicare-participating provider nationwide, with no networks or referrals required.
Learn about Medicare Supplement →Frequently Asked Questions
What does Medicare Part B cover?
Medicare Part B is medical insurance. It covers medically necessary outpatient services including doctor visits, preventive screenings, lab tests, imaging, durable medical equipment (DME), outpatient surgery, and mental health services. Part B also covers some home health services and certain drugs administered in a clinical setting (not self-administered prescriptions — those are Part D).
How much does Medicare Part B cost in 2025?
The standard Medicare Part B premium in 2025 is $185.00 per month. This applies to most enrollees. If your income exceeds certain thresholds, you pay an Income Related Monthly Adjustment Amount (IRMAA) surcharge on top of the standard premium. The Part B annual deductible in 2025 is $257. After the deductible, Medicare pays 80% of approved costs and you pay the remaining 20%.
What is the Medicare Part B late enrollment penalty?
If you do not enroll in Medicare Part B when first eligible and do not have other creditable coverage, you may owe a late enrollment penalty. The penalty is 10% of the standard premium for each full 12-month period you were eligible but did not enroll. This penalty is permanent — it is added to your premium for as long as you have Part B.
What is IRMAA and how does it affect my Part B premium?
IRMAA stands for Income Related Monthly Adjustment Amount. If your modified adjusted gross income (MAGI) from two years ago exceeds certain thresholds, Social Security adds a surcharge to your Part B premium. In 2025, IRMAA tiers range from an additional $74.00/mo to $443.90/mo depending on income. If your income has dropped significantly, you can appeal your IRMAA using Form SSA-44.
What counts as creditable coverage for Medicare Part B?
Creditable coverage for Part B purposes means you have health insurance through active employment (your own or a spouse's) at a company with 20 or more employees. If your employer coverage is considered creditable, you can delay Part B enrollment without penalty. COBRA, retiree coverage, and individual marketplace plans generally do not count as creditable coverage for avoiding the Part B late penalty.
When should I enroll in Medicare Part B?
You should generally enroll in Part B during your 7-month Initial Enrollment Period — 3 months before, the month of, and 3 months after your 65th birthday. If you have creditable employer coverage from active employment, you can delay without penalty using a Special Enrollment Period when you or your spouse leave that job. Delaying without creditable coverage results in a permanent late enrollment penalty.
Questions about your Part B coverage?
A local licensed Medicare plan specialist can explain your Part B costs, help you avoid the late enrollment penalty, and find supplemental coverage that eliminates the 20% gap — free, no pressure.
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