How IRS Filing Status Affects Medicare Part B and D Premiums

Medicare Part B and Part D premiums are influenced by an individual's income as reported in their IRS tax returns, specifically from two years prior to enrollment, but the IRS tax filing status itself does not determine Medicare eligibility. The Income-Related Monthly Adjustment Amount (IRMAA) establishes income thresholds that impact the premium costs for Medicare Part B and D, with separate thresholds for those filing as single versus married filing jointly. For example, in 2025, the IRMAA threshold is $106,000 for singles and $212,000 for those married filing jointly, and exceeding these thresholds results in higher premiums. Importantly, Medicare coverage is individual and not based on spousal income or filing status, but premium calculations consider combined income when filing jointly. The article advises consulting tax professionals to determine the most financially advantageous tax filing status prior to enrolling in Medicare, as this can affect the income considered in premium calculations. Additionally, individuals with employer-sponsored creditable group health insurance may delay Medicare enrollment without penalty until employer coverage ends, potentially avoiding immediate premium costs. The article emphasizes the need to monitor annual changes in IRMAA thresholds and to plan Medicare enrollment accordingly based on income and coverage status.