What you will learn: this updated November 2026 guide shows retirement planners how to stage Roth conversions in the 5–10 years before required minimum distributions (RMDs) begin so you can smooth taxable income, lower future RMDs, limit Medicare IRMAA surcharges, and reduce the share of Social Security that becomes taxable. It is written for retirement-planning enthusiasts who want a practical, year-by-year plan they can implement or discuss with an advisor.

Prerequisites and context

Before you start: know these policy and practical facts that shape conversion decisions in 2026.

  • RMD age under SECURE 2.0: SECURE 2.0 (2022) raised the RMD start age to 73 for most people beginning in 2023, with a scheduled increase to 75 in 2033. That means many readers have a 5–10 year window before their first RMD — a prime time to stage conversions.
  • Conversions are irreversible: Roth conversion recharacterizations (undoing a conversion) were eliminated several years ago. Treat each conversion as final; plan carefully.
  • Medicare IRMAA and timing: Medicare Part B/D IRMAA surcharges are assessed based on your modified adjusted gross income (MAGI) two years prior to the benefit year. Conversion timing therefore affects Medicare premiums with a two-year lag.
  • Tax brackets and thresholds are indexed: Federal brackets, the standard deduction and IRMAA/Social Security thresholds are adjusted annually for inflation. Always check current-year numbers before finalizing conversion amounts.
  • Five‑year rule and penalty timing: Each Roth conversion triggers its own five‑tax‑year clock for purposes of avoiding the 10% early‑withdrawal penalty on distributed conversion amounts if you are under age 59½.

Why stage Roth conversions before RMDs? (Updated 2026)

The core rationale has not changed, but two near-term dynamics make staging conversions especially relevant in 2026:

  • Longer pre-RMD window for many: With the RMD start at 73, more people approaching retirement have an extended planning horizon to shift taxable balances into Roth accounts.
  • IRMAA pressure and MAGI management: Medicare premium surcharges have become a more visible line-item for retirees. Because IRMAA is determined on MAGI two years earlier, conversions timed correctly can reduce lifetime Medicare costs.

Staging conversions across multiple years can:

  • Smooth annual taxable income and avoid single-year spikes that push you into higher marginal tax brackets.
  • Reduce the tax-deferred balance that produces future RMDs.
  • Lower provisional income used to determine how much of your Social Security is taxed.
  • Manage MAGI in years that determine Medicare IRMAA surcharges.

High-level roadmap (revised for 2026)

  1. Take a full inventory of balances, income streams and state residency.
  2. Model year-by-year taxable income, RMDs and MAGI for at least the first 10 years of retirement under several conversion scenarios.
  3. Set annual conversion targets that “fill” available tax-bracket space and avoid bumping into IRMAA or Social Security thresholds in key years.
  4. Coordinate conversions with pension elections, rollovers, Social Security claiming, and any planned QCDs (qualified charitable distributions).
  5. Execute early in the year where practical, document each conversion, and re-run projections annually (or after major life or market changes).

Step 1 — Full financial inventory (updated checklist)

Document everything that affects taxable income and RMDs:

  • 401(k) and employer plan balances and in-plan Roth options — can you roll to an IRA?
  • Traditional IRA balances and historical nondeductible contributions (basis)
  • Roth IRAs and Roth 401(k) balances
  • Taxable brokerage and cash accounts you can use to pay conversion taxes
  • Pension choices, lump-sum availability and projected start dates
  • Estimated Social Security benefit at different claiming ages
  • Other recurring income: rental, consulting, part-time work, deferred comp
  • State of residence and any planned moves (state tax changes can swing the math)

Action: compile the most recent statements and calculate a baseline “do-nothing” RMD projection using IRS life expectancy tables or a planning tool. If your projected RMDs are small relative to your balances, conversions may not pay.

Step 2 — Forecast taxable income and thresholds

Create at least three scenarios: conservative (minimal conversions), moderate (fill lower brackets), and aggressive (larger conversions to substantially reduce future RMDs). Key inputs:

  • Projected RMDs under current balances and growth assumptions
  • Planned pension start dates and Social Security claiming ages
  • MAGI build-up and years that map to Medicare IRMAA determinations
  • State income-tax rules for conversions

Practical modeling tips:

  • Anchor models to current-year brackets but run sensitivity cases with bracket compression/expansion and MAGI threshold shifts.
  • Include a two-year lag when assessing the IRMAA impact of a conversion (a 2026 conversion affects 2028 Medicare premiums).
  • Check whether your state taxes Roth conversions — some states offer favorable treatment, others do not.

Step 3 — Set annual conversion targets

Use these decision rules to set yearly amounts:

  1. Identify “tax bracket fill” targets: convert up to the top of a lower federal bracket in years before RMDs so you pay tax at lower marginal rates rather than higher future rates.
  2. Aim to keep MAGI below IRMAA and Social Security taxation breakpoints in the critical years that determine premiums and benefit taxation.
  3. Confirm you can pay the conversion tax from outside funds (taxable account, current income) — avoid using converted funds to pay tax when possible.

Note the Roth five‑year rule: each conversion starts a five-tax-year clock for penalty avoidance on converted principal if you are under 59½. If you expect to withdraw converted dollars early, plan conversions after age 59½ or accept the rule’s constraints.

Step 4 — Coordinate with pensions, rollovers, and Social Security

Key coordination points:

  • Pension choices: A lump-sum that goes into an IRA increases your pre-tax base; include that in conversion modeling before electing. An annuity income stream changes annual taxable profiles.
  • 401(k) rollovers: Rolling a 401(k) into a traditional IRA often simplifies conversion mechanics, but check plan rules and any creditor protections that may differ by state.
  • Social Security timing: Conversions increase MAGI in the year of conversion and can increase the taxable portion of benefits. If you plan to start Social Security soon, weigh converting before or after claiming — a conversion in a year when benefits are suspended or small may have less impact on benefit taxation.
  • Medicare enrollment: Remember the two-year MAGI lookback when you plan conversions near Medicare enrollment dates.

Step 5 — Implement and monitor

Execution best practices:

  • Do conversions early in the tax year to allow re-calibration later in the year if markets or income change.
  • Document each conversion: date, source account, amount converted, tax paid, and the tax lot year for five-year-rule tracking.
  • Pay taxes from non-retirement funds when possible to preserve Roth principal and long-term growth.
  • If markets drop after you convert, the conversion will have locked in a lower basis (you can’t undo it), which is good in retrospect — but avoid market-timing; use dollar-cost averaging across years if you want to reduce timing risk.
  • Re-run projections at least annually and after any major life event (move, large gift, pension election, job change, market drawdown).

Illustrative example — updated for 2026 (hypothetical)

Jamal, age 66 in 2026, has a $850,000 traditional IRA and expects to begin RMDs at 73. He anticipates a $24,000/year pension starting at 71 and Social Security of $36,000/year if claimed at full retirement age. Jamal can pay taxes from his $200,000 taxable brokerage account. His planner models a nine-year conversion window (age 67–75) but focuses conversions in the 67–72 window to affect Medicare premiums in the years that matter.

They set a target of converting roughly $35,000–$40,000 per year to fill lower tax-bracket space and keep projected MAGI below known IRMAA breakpoints in the two-year lookback windows. Over six years Jamal converts $225,000, paying taxes from his brokerage account. The model shows lower RMDs at 73 and reduced MAGI in IRMAA-relevant years, producing cumulative Medicare premium savings that more than offset taxes paid on the conversions in the planner’s baseline scenario.

Outcome depends on actual investment growth, future tax-law changes, and Jamal’s longevity assumptions; this is a concrete starting plan to test and adjust annually.

Common mistakes and how to avoid them (refreshed)

  • Converting a single large chunk just before RMDs: That recreates the income spike you’re trying to avoid. Instead, stagger conversions over several years.
  • Paying conversion tax from the converted amount: This reduces Roth principal and the long-term tax-free growth benefit.
  • Ignoring the two-year Medicare MAGI lookback: A conversion can raise premiums two years hence; plan timing accordingly.
  • Overlooking state tax consequences: Some states tax conversions, cap deductions, or treat Roths differently. If you plan to move states, model before and after the move.
  • Forgetting the five‑year rule and recharacterization ban: Conversions cannot be undone; each conversion has its own five-year penalty clock if you are under 59½.

Pro tips (advanced planning ideas)

  • Use partial conversions to fill up to the top of a favorable federal bracket rather than converting to an arbitrary dollar goal.
  • Coordinate conversions with years you expect lower income (e.g., early retirement years with no Social Security, or years you take a temporary sabbatical that reduces wage income).
  • Consider QCDs (qualified charitable distributions) from IRAs to reduce MAGI in years when you must take RMDs — these can be combined with conversions in a holistic plan.
  • Run “what-if” scenarios that include potential legislative changes: if you expect tax rates to rise, accelerate conversions; if you expect a lower-income later phase, be more conservative.
  • Leverage modern planning tools — eMoney, MoneyGuidePro or cash-flow modeling — to project MAGI and IRMAA impacts two-to-ten years forward.

Checklist — year‑by‑year practical steps

  1. Year 0 (5–10 years pre‑RMD): Gather statements, project RMDs, and model scenarios.
  2. Year 1: Choose an annual conversion target; confirm you can pay taxes from non-retirement funds.
  3. Each year: Re-run projections early in the year; execute conversion(s) early; document.
  4. Two years before Medicare enrollment: Re-check MAGI in the two-year lookback and adjust conversion pace to limit IRMAA.
  5. At RMD age: Confirm reduced traditional balance and recalculate expected RMDs for the coming year.

When conversions may not be right

  • You cannot pay the conversion tax without depleting retirement principal.
  • Your life expectancy or wealth goals make the tax-free growth inside a Roth unlikely to pay off.
  • You expect substantially lower taxable income in RMD years (e.g., large pension offset or planned move to a no-income-tax state) that makes conversions less economical.

Working with professionals

Roth conversion staging intersects federal tax, Social Security, pension design and Medicare rules. Work with a tax-aware CFP® or CPA who will:

  • Run year-by-year MAGI and IRMAA projections with the two-year lookback hard-coded
  • Model the effect of conversions on future RMDs and net retirement cash flow
  • Include state-tax scenarios and pension-lump-sum versus annuity trade-offs

Bottom line

Staged Roth conversions remain one of the most effective, controllable levers retirees have to smooth taxable income and lower lifetime exposure to high marginal tax brackets, Medicare IRMAA surcharges, and Social Security taxation. In 2026 the extended pre‑RMD window for many (RMD age 73) and the continued sensitivity of Medicare premiums to MAGI make deliberate, model-driven conversion plans especially valuable. Start early, convert in manageable amounts timed around MAGI and Medicare lookbacks, pay taxes from outside funds, document carefully, and revisit the plan annually.

Frequently asked questions

How does a Roth conversion affect Medicare premiums (IRMAA)?

Medicare Part B and D surcharge amounts (IRMAA) are based on your modified adjusted gross income (MAGI) from two years earlier. A conversion increases MAGI in the year you do it and therefore can increase premiums two years later. Plan conversions with the two‑year lookback in mind—if you’re near Medicare enrollment, consider doing conversions earlier or later to avoid a spike in IRMAA.

Can I undo a Roth conversion if markets fall after I convert?

No. Roth conversion recharacterizations (undoing a conversion) were eliminated several years ago. If markets decline after a conversion you cannot reverse it. That risk argues for staggering conversions over multiple years rather than converting a very large amount in a single year.

Do conversions affect my Social Security taxation?

Yes. The taxable portion of Social Security benefits is based on provisional income, which includes MAGI. A conversion increases MAGI and can raise the share of benefits that are taxable in the same tax year. Coordinate conversions with your Social Security claiming strategy to minimize unwanted benefit taxation.

Should I pay conversion taxes from the converted IRA funds?

Generally no. Paying conversion taxes from non-retirement savings preserves more Roth principal for tax-free growth. Using converted balances to pay taxes reduces the net benefit and is often less tax-efficient, particularly for larger conversions.

How do state taxes affect the decision to convert?

State tax rules can materially change conversion economics. Some states tax IRA distributions the same as federal rules; others exempt pensions or offer partial exclusions for retirement income. If you plan to move states around retirement, model conversions both under current residency and the planned state of residence.