Medicare Part B Premium
The Medicare Part B premium is the monthly amount paid by beneficiaries for Medicare outpatient coverage, including physician visits, outpatient hospital care, preventive services, and durable medical equipment — with standard and income-adjusted amounts set annually by the Centers for Medicare and Medicaid Services.
Medicare Part B covers medical insurance — the outpatient component of Original Medicare. Unlike Part A (hospital insurance), which most beneficiaries receive premium-free based on their work history, Part B requires a monthly premium payment. The standard Part B premium for 2025 is $185.00 per month. Most Part B beneficiaries pay the standard premium, but higher-income individuals pay an Income-Related Monthly Adjustment Amount (IRMAA), which can substantially increase the effective cost of Part B coverage.
IRMAA is calculated based on the beneficiary's Modified Adjusted Gross Income (MAGI) from two years prior. For 2025, the IRMAA determination uses 2023 MAGI. The thresholds create several income brackets above the standard premium: individuals with MAGI exceeding $106,000 (couples exceeding $212,000) begin paying IRMAA surcharges, with the highest bracket (MAGI above $500,000 individual or $750,000 joint) resulting in a total monthly Part B premium of $628.90 in 2025. IRMAA surcharges are assessed separately for Part D (prescription drug coverage) as well.
The two-year look-back for IRMAA creates situations where a one-time high-income year — from a business sale, large Roth conversion, or large capital gain — triggers premium surcharges two years later. Beneficiaries can appeal IRMAA using Social Security Form SSA-44 if their income has decreased since the base year due to a qualifying life-changing event (marriage, divorce, death of a spouse, loss of pension, or a work cessation event). Proactive retirement income planning that manages MAGI in years before Medicare eligibility can meaningfully reduce long-term IRMAA exposure.
Part B premiums are typically deducted directly from Social Security benefit payments for enrolled beneficiaries. Individuals enrolled in Part B who are not yet receiving Social Security must pay premiums quarterly or set up direct billing. Part B premiums paid are deductible as a qualified medical expense for HSA purposes (if the account holder is 65 or older and enrolled in Medicare) and may be deductible on Schedule A for taxpayers who itemize.
The annual open enrollment period for Medicare Advantage and Part D plans (October 15 – December 7) is separate from the Part B enrollment window. Initial Part B enrollment should occur during the Initial Enrollment Period beginning three months before the month of 65th birthday to avoid late enrollment penalties of 10% per 12-month period of delayed enrollment.