Medicare Open Enrollment 2027: What High-Earner Retirees Must Check Before December 7

Medicare Open Enrollment for 2027 runs from October 15 through December 7, 2026. During this period, beneficiaries can change Medicare Advantage coverage, switch or select a Part D prescription drug plan, or move between Medicare Advantage and Original Medicare. Changes generally take effect January 1, 2027, provided the plan receives the enrollment request by December 7. The official Medicare Open Enrollment guide outlines the available options.

For high-earner retirees, the deadline is also a timely prompt to review how income, plan costs, and tax decisions interact. The most useful review goes beyond comparing premiums: it considers whether a prior-year income spike may affect Medicare surcharges, whether the selected drug plan still fits, and how future Roth conversions could influence later premiums.

1. Check which income year may affect 2027 IRMAA

The Income-Related Monthly Adjustment Amount, or IRMAA, is an income-based surcharge added to Medicare Part B and Part D costs for beneficiaries whose income exceeds specified limits. Social Security generally uses federal tax information from two years earlier when determining IRMAA. For 2027, that ordinarily means the beneficiary’s 2025 tax return.

For this purpose, modified adjusted gross income (MAGI) generally consists of adjusted gross income plus tax-exempt interest. Filing status also matters, so a married couple filing jointly should not assess the potential impact using an individual threshold.

As of October 16, 2026, official 2027 IRMAA thresholds and surcharge amounts had not yet been published in the sources reviewed for this article. Retirees should therefore avoid relying on unofficial estimates as final figures. The 2026 amounts are not a substitute for the 2027 schedule, and the eventual Social Security determination notice is the relevant statement of an individual’s assessed premium.

A practical first step is to locate the 2025 federal return and identify the applicable MAGI and filing status. This will help retirees anticipate whether a surcharge may apply once 2027 figures are available, without mistaking an estimate for an official assessment.

2. Consider whether a one-time income spike can be addressed

A business sale, large Roth conversion, or substantial realized capital gain in 2025 may have raised MAGI enough to affect 2027 IRMAA. Under the ordinary two-year lookback, the source of that income does not automatically remove it from the calculation.

There is, however, a process for seeking a lower IRMAA when a qualifying life-changing event has reduced income. Social Security Form SSA-44 allows a beneficiary to ask Social Security to use more recent income information in certain circumstances. Qualifying events can include marriage, divorce or annulment, the death of a spouse, work stoppage or work reduction, loss of income-producing property under qualifying circumstances, loss of pension income, or an employer settlement payment.

The distinction between an income spike and a qualifying event is important. A Roth conversion or realized gain, by itself, is not a qualifying SSA-44 event. A business sale does not automatically qualify merely because the sale produced taxable income. A business owner who also stopped or substantially reduced work may have a potential qualifying event, but eligibility depends on the circumstances and supporting documentation.

The form requires information about the event and the beneficiary’s more recent or estimated MAGI, along with evidence. Depending on the event, that evidence may include employer documentation, a pension administrator’s statement, or official records. The SSA guidance on requesting a lower IRMAA explains the process. If a beneficiary disagrees with the determination itself for another reason, that is distinct from an SSA-44 request and may require a formal reconsideration.

3. Reassess the Part D plan, not just its premium

Prescription drug coverage can change from year to year. During Open Enrollment, beneficiaries should compare the 2027 plan’s premium, deductible, covered medications, pharmacy network, and cost-sharing rules with their current coverage. A plan that served well in 2026 may have a different formulary, pharmacy arrangement, or cost structure for the coming year.

The plan’s stated premium is not necessarily the full Part D cost for a higher-income beneficiary. Part D IRMAA is a separate income-based surcharge, added to the premium of the selected drug plan. It does not replace the plan premium. For that reason, a low-premium plan may still carry a meaningful total cost once the surcharge and expected prescription expenses are considered.

The Medicare Plan Compare tool lets beneficiaries review available coverage and plan details. Medicare Advantage members should also examine provider networks and other coverage terms, while people considering a switch to Original Medicare should review the related coverage requirements. In particular, Medicare notes that access to Medigap can be limited by timing and eligibility rules.

4. Connect Medicare costs with Roth conversion and bracket planning

Medicare timing is relevant to tax planning because a Roth conversion can increase taxable income and, in turn, MAGI. For a conversion completed in 2025, the resulting income may be reflected in the 2027 IRMAA calculation. A conversion completed in 2026 would ordinarily be considered in a later premium year, subject to Social Security’s normal lookback and the tax information available.

That timing does not make a Roth conversion inherently unsuitable. A conversion may support long-term tax diversification or reduce future tax exposure, but its value depends on the full household picture. Retirees may need to assess the current-year tax bracket, potential IRMAA effects in later years, required minimum distributions, and the effect of taxable income on other parts of the tax return.

Thresholds deserve particular attention. A conversion that moves MAGI into a higher IRMAA tier may increase Medicare costs in addition to the conversion’s income-tax consequences. Conversely, minimizing income in a single year is not automatically the best long-term strategy if it leaves larger taxable distributions or less flexibility later. These decisions benefit from coordinated tax and retirement-income analysis rather than a single-year premium calculation.

5. Treat the December 7 deadline as one part of a broader review

Before the deadline, retirees can use a concise review process:

• Confirm coverage needs: Review current medications, preferred pharmacies, providers, and anticipated care.
• Compare 2027 plan details: Check premiums, deductibles, formularies, networks, and cost-sharing through Medicare’s plan comparison tool.
• Review 2025 income: Note MAGI and filing status to help assess possible IRMAA exposure when official 2027 figures become available.
• Examine unusual income: If a qualifying life-changing event reduced income, review SSA-44 requirements and assemble supporting documentation.
• Coordinate future tax moves: Evaluate how planned conversions and other income decisions could affect later Medicare costs.

The most resilient approach is not simply to select the lowest visible premium. It is to coordinate health coverage with a durable retirement-income strategy, recognizing that income decisions can influence both taxes and Medicare costs over multiple years. Provident Capital Group’s retirement planning and tax strategy services address these considerations as part of a broader financial plan.

Author: John E. Miller, Senior Wealth Advisor at Provident Capital Group, brings 27 years of experience in financial planning, investment advisory, and wealth management. His work focuses on helping individuals and families make informed decisions about retirement, income, and long-term financial goals. Learn more about John E. Miller or contact Provident Capital Group.

This article is for informational purposes only and is not tax, legal, or Medicare advice. Medicare premiums, IRMAA thresholds, plan terms, and eligibility rules are subject to change. Beneficiaries should confirm current information with Medicare, Social Security, and their qualified tax or financial professionals.