Understanding Medicare Part B: Coverage, Costs, and Enrollment in 2026

Part B covers two main categories of services: medically necessary services and preventive services.

Medically necessary services are services or supplies needed to diagnose or treat a medical condition and that meet accepted standards of medical practice. This includes:

Preventive services are covered at 100% with no cost-sharing when provided by a participating provider. Key preventive services include:

What Part B does NOT cover: Routine dental care, routine vision exams, hearing aids, most prescription drugs, long-term custodial care, and cosmetic procedures.

Understanding Part B costs helps you budget accurately and compare it against alternative coverage options.

Standard premium: $185.00 per month in 2026. This is deducted automatically from your Social Security benefit if you receive Social Security. If you are not yet receiving Social Security, you are billed quarterly.

IRMAA surcharges: Higher-income beneficiaries pay more. IRMAA surcharges are based on your income from 2 years ago (2024 income determines 2026 IRMAA). The surcharges range from an additional $74.00 to $443.90 per month in 2026.

Annual deductible: $257 in 2026. You pay 100% of covered Part B costs until you meet this deductible each calendar year.

Coinsurance: After the deductible, Medicare pays 80% of the Medicare-approved amount for most covered services. You pay the remaining 20%. There is no annual cap on your 20% coinsurance under Original Medicare alone.

Excess charges: If a provider does not accept Medicare assignment (meaning they charge more than the Medicare-approved amount), they can charge up to 15% above the approved amount. This is called an excess charge. Most Florida providers accept assignment, but it is worth confirming.

Part B enrollment timing is one of the most important Medicare decisions you will make. Getting it wrong results in a permanent penalty.

Initial Enrollment Period (IEP): Your IEP is a 7-month window: 3 months before the month you turn 65, the month you turn 65, and 3 months after. Enrolling in the first 3 months of your IEP ensures your coverage starts on the first day of your birthday month.

If you are already receiving Social Security: You are automatically enrolled in Part A and Part B when you turn 65. You will receive your Medicare card in the mail approximately 3 months before your 65th birthday.

If you have qualifying employer coverage: You can delay Part B enrollment without penalty if you are covered by an employer plan through your own or your spouse's current employment at an employer with 20 or more employees. You enroll during your Special Enrollment Period (up to 8 months after losing employer coverage).

General Enrollment Period: If you miss your IEP and do not have qualifying employer coverage, you can enroll during the General Enrollment Period (January 1 to March 31 each year). Coverage starts July 1. You will also face the late enrollment penalty.

For a detailed guide to enrollment timing, see our article on how to sign up for Medicare step by step.

The Part B late enrollment penalty is one of the most consequential Medicare rules to understand. It is permanent, and it compounds with each year of delay.

How the penalty is calculated: For every 12-month period you were eligible for Part B but did not enroll (without qualifying employer coverage), your premium increases by 10%. This surcharge is added to your standard premium and lasts for as long as you have Part B.

Example: If you delay Part B for 3 years without qualifying employer coverage, your penalty is 30%. At the 2026 standard premium of $185.00, that adds $55.50 per month permanently. Over 20 years of retirement, that is more than $13,000 in extra premiums.

The penalty does not apply if you have qualifying employer coverage: If you delay Part B because you are covered by an employer plan through current employment at a 20+ employee company, no penalty applies. The penalty only applies to periods without qualifying coverage.

IRMAA and the penalty stack: If you are subject to IRMAA surcharges, the late enrollment penalty is calculated on top of the standard premium, not the IRMAA-adjusted premium. However, you still pay both surcharges.

For more on managing Part B costs, see our guide on how to reduce Medicare premiums based on income.

Part B alone leaves significant gaps in coverage. Understanding how it fits with other parts of Medicare helps you build a complete coverage strategy.

Part B + Part A = Original Medicare: Together, Part A (hospital) and Part B (medical) form Original Medicare. This covers the majority of your healthcare needs but leaves you responsible for the 20% coinsurance with no annual cap.

Adding a Medigap supplement: A Medigap plan covers some or all of the 20% coinsurance that Part B leaves. Plan G, the most popular option in Florida, covers everything except the Part B deductible. This gives you predictable, capped costs for medical services.

Adding Part D: Part B does not cover most prescription drugs. You need a standalone Part D plan or a Medicare Advantage plan with drug coverage to cover your medications.

Medicare Advantage as an alternative: Medicare Advantage (Part C) replaces Original Medicare. It covers everything Part A and Part B cover, usually with lower premiums but with network restrictions and different cost-sharing structures.

For a full comparison of your coverage options, see our guide on Original Medicare vs. Medicare Advantage in Florida. For personalized guidance, schedule a free consultation with our licensed specialists.