What you will learn: This updated October 2026 guide shows retirement-focused readers how to plan Roth conversions, manage required minimum distributions (RMDs), and reduce Medicare IRMAA surcharges without creating harmful income “spikes.” It’s written for anyone approaching or already in their 60s–70s with traditional retirement accounts, a pension, or planned Social Security claiming.

Prerequisites and context (what to know first)

Before acting, confirm these baseline rules that drive the analysis:

  • RMD age: As of October 2026 most account owners begin RMDs at age 73 (this change was enacted in the SECURE 2.0 legislation and applies to people who reach the prior RMD age after the law’s effective dates). Confirm your personal RMD start year with your custodian or advisor.
  • IRMAA lookback: Medicare Part B and Part D premiums are adjusted upward when your modified adjusted gross income (MAGI) from two years earlier exceeds thresholds. MAGI for IRMAA equals your AGI plus tax-exempt interest; taxable RMDs, pension income, and the taxable portion of Social Security increase MAGI.
  • Roth conversions: Converting pre-tax retirement funds to a Roth IRA is taxable in the conversion year and therefore increases MAGI for the two-year IRMAA lookback. Qualified Roth withdrawals (once rules are met) do not count as taxable income.
  • IRMAA appeals: If your income falls due to a life-changing event (retirement, death of a spouse, divorce, etc.), you can request reconsideration using SSA form SSA‑44 and supporting documentation.

Why this matters now (October 2026)

Two practical realities make timing critical in 2026:

  • RMDs are now commonly starting at 73 for most cohorts, so many retirees face larger taxable distributions earlier (and larger year-to-year increases) than before.
  • Medicare IRMAA still uses a two-year lookback, so a Roth conversion timed in a low-income year can reduce lifetime taxable RMDs—but a single large conversion can raise Medicare premiums for multiple future years.

Step-by-step plan

1. Run two forward-looking income projections

  1. Project taxable income annually from now through age 76–78. Include estimated RMDs (use your custodian’s RMD calculator or IRS life-expectancy tables), pension payments, the taxable portion of Social Security, expected Roth conversions, and any other taxable events (lump-sum distributions, capital gains, etc.).
  2. Build a separate “two-year lookback” view: each calendar year’s MAGI will determine Medicare IRMAA two years later. Flag years where projected MAGI crosses common IRMAA steps.
  3. Use conservative assumptions: assume modest investment growth, Social Security cost-of-living adjustments, and potential pension COLAs if applicable. Re-run projections annually or when circumstances change.

2. Identify true low-income conversion windows

Look for years when you will have unusually low taxable income — for example, early retirement years after wages stop but before RMDs and before Social Security begins. Those years offer the best tax efficiency for Roth conversions because:

  • Your marginal tax rates are lower, so you pay less tax per dollar converted.
  • Avoiding a one-year MAGI spike reduces the risk of pushing you into a higher IRMAA bracket that will apply two years later.

3. Size conversions to avoid IRMAA “cliffs”

Partial conversions spread over several years usually work better than one large conversion. Practical steps:

  1. Identify the IRMAA thresholds relevant to you for each lookback year (check SSA’s current table). Use those as hard caps for MAGI in your projection model.
  2. Decide a target annual conversion amount that keeps projected MAGI under the nearest IRMAA threshold. If you can’t keep under the threshold, size conversions to limit movement into the next IRMAA band.
  3. Example (hypothetical): A married couple projects taxable income of $110,000 (pension + taxable Social Security + RMDs) and sees an IRMAA surcharge step at $140,000. Rather than converting $100,000 in one year (which would trigger surcharges), convert $15,000–$20,000 annually when income is low until the Roth balance is sufficient to meaningfully reduce future RMDs.

4. Coordinate Social Security claiming

Social Security claiming affects both near-term cashflow and taxable income. Practical approaches:

  • If you have a low-income window and plan Roth conversions, consider delaying Social Security until after those conversions are done to minimize the taxable portion of benefits and avoid simultaneously increasing MAGI with conversions and Social Security.
  • If delaying benefits is financially optimal overall (higher future benefits), sequence conversions in years before benefits start. If you must claim earlier for cashflow, reduce conversion size that year.

5. Choose the right account pathways

Account mechanics affect flexibility and taxes:

  • Roll pre-tax 401(k) funds into a traditional IRA if you need the ability to do Roth conversions that your employer plan disallows. Confirm loan or withdrawal features and creditor protections before rolling.
  • Use in-plan Roth conversions if allowed and advantageous — they may offer easier payroll-based conversions or different protections, but check plan rules and fees.
  • Remember: Roth conversions are taxable in the conversion year and add to MAGI for IRMAA calculations.

6. Use pension start dates and distribution options strategically

Smaller timing choices can alter which tax year income is recognized in and therefore which IRMAA lookback year is affected:

  • If your pension allows you to shift the start date by months, move the first payment into or out of a year to control MAGI relative to IRMAA thresholds.
  • Evaluate lump-sum buyouts carefully. A lump-sum will spike MAGI and likely increase Medicare premiums for future years; only consider if actuarial trade-offs and estate planning needs justify the tax hit.

7. Use other MAGI-management tools

Complement Roth conversions with these tactics:

  • Qualified charitable distributions (QCDs): If eligible, QCDs remove IRA dollars from taxable income by donating directly to charities. (Confirm current IRS rules and minimum age before using QCDs.)
  • Tax-loss harvesting in taxable accounts to offset capital gains that would increase MAGI.
  • Municipal bond interest is tax-exempt but still counts toward MAGI via tax-exempt interest; include it in projections to avoid surprises.

8. Monitor, document and file IRMAA appeals when appropriate

If IRMAA is assessed due to a high-income year and your income subsequently drops because of retirement, divorce, death of a spouse, or permanent disability, file an appeal with SSA using form SSA‑44. Steps:

  1. Collect documentation: recent tax returns, employer letters, pension statements, or settlement documents showing reduced income.
  2. File promptly and follow up. Keep copies of all correspondence.
  3. Plan around the appeals timeline: even if you expect a successful appeal, the premiums may be charged initially and refunded if the appeal is granted.

Common mistakes to avoid

  • Converting a large balance in a single year without modeling IRMAA consequences for the lookback years two years later.
  • Failing to include tax-exempt interest (municipal bonds) in MAGI projections—this can unexpectedly push you into IRMAA territory.
  • Overlooking pension start-date flexibility or lump-sum trade-offs because the timing can shift taxable income into different IRMAA lookback years.
  • Assuming Roth conversions always lower lifetime taxes—Roth makes sense when you expect higher marginal tax rates later or if you value IRMAA/premium reduction; run scenarios.

Pro tips (advanced)

  • Run sensitivity analyses: model multiple scenarios (best case, baseline, worst case) with different investment returns, Social Security claiming ages, and life expectancy assumptions.
  • If you expect to be in a higher tax bracket later (due to large inheritances or rising policy rates), prioritize earlier Roth conversions even if they slightly increase near-term taxes.
  • Coordinate with your estate plan. Roth IRAs do not create RMDs for original owners and are often preferred for heirs; factor estate tax exposure into conversion sizing.
  • Review in-plan Roth rules annually. Since 2023 many plans expanded in-plan Roth options; employers and plan administrators update operations regularly.

Practical calendar: ages 62–76 (action timeline)

  1. Ages 62–67 (pre-Medicare): Build 8–10 year projections. Identify candidate low-income conversion years. Consider rolling 401(k) balances to IRAs only if needed for conversion flexibility.
  2. Ages 67–70: Execute partial Roth conversions in identified low-income years. Avoid large conversions in years you expect to claim Social Security unless projections show room under IRMAA thresholds.
  3. Ages 70–73: Medicare enrollment years — be especially cautious. Remember conversions at 71 affect IRMAA when you enroll at 73. Re-evaluate each year and pause conversions if they will create outsized IRMAA.
  4. Ages 73–76 and beyond: RMDs grow; the Roth balance you accumulated earlier will lower taxable RMDs. Continue smaller conversions only if they won’t trigger higher IRMAA and if tax-efficiency justifies them.

Checklist before you act

  • Project MAGI for the next 6–8 years, explicitly including RMDs, pension, taxable Social Security, and tax-exempt interest.
  • Identify SSA/Medicare IRMAA thresholds for the years that will be used in the two-year lookback.
  • Decide the Roth balance target that meaningfully reduces future RMDs for your cashflow needs.
  • Plan conversion amounts and schedule to avoid one-year MAGI spikes that produce multi-year IRMAA surcharges.
  • Confirm in-plan Roth options and rollover rules with plan administrators.
  • Engage a fee-only financial planner and tax advisor for complex situations (large balances, pensions with survivor options, or state tax considerations).

Bottom line

In October 2026 the core playbook remains the same but the stakes have shifted: earlier RMDs for many (RMD age 73), the persistent two-year Medicare lookback, and continued uncertainty about future tax policy mean planning and sequencing matter more than ever. The practical path is to project forward, seize genuine low-income years for measured Roth conversions, coordinate Social Security and pension timing, and avoid single-year income spikes that raise Medicare premiums for years. With careful modeling and annual reviews you can materially lower lifetime Medicare premiums and taxes while preserving flexibility.

FAQ

Will a Roth conversion always reduce my Medicare premiums?

No. A Roth conversion increases your MAGI in the conversion year and therefore can raise Medicare IRMAA surcharges two years later. Conversions reduce future taxable RMDs, which can lower premiums later — but only if you time and size conversions to avoid a harmful one-year spike. Model both short- and medium-term effects before converting.

What counts as MAGI for IRMAA?

For IRMAA purposes, MAGI is your adjusted gross income plus tax-exempt interest (for example, municipal bond interest). Taxable RMDs, pension income, and the taxable portion of Social Security all increase MAGI and thus can trigger IRMAA.

Can I appeal an IRMAA decision if my income drops?

Yes. If your IRMAA was based on a high-income year and your income later drops because of retirement, death of a spouse, divorce, or other life-changing events, you can request reconsideration from the Social Security Administration using form SSA‑44 and supporting documentation. Keep detailed records and follow the SSA instructions carefully.

Should I roll my 401(k) to an IRA to do Roth conversions?

Only if you need the conversion flexibility your 401(k) doesn’t offer. Some employer plans permit in-plan Roth conversions, and some provide creditor protections or loan features that an IRA does not. Compare fees, protection differences, and conversion rules before moving balances.

How often should I update my plan?

Annually, and any time circumstances change materially (pension election, unexpected inheritance, major market moves, health changes, or change in claiming strategy for Social Security). Re-run the two-year lookback projections each year and before any large distribution or conversion.