Executive Summary

In June 2026 Mark (67) and Elena (66) completed a primary-residence sale and used the $500,000 married exclusion to convert a portion of their $1.35M pre-tax retirement balance to Roth IRAs in staged annual steps. They funded conversion taxes from taxable proceeds, preserved Roth principal for compounding, reduced projected RMD-driven taxable income in their 70s, and tilted their estate toward tax-free assets for heirs.

Background

Subjects: Mark (67) and Elena (66), married filing jointly, retired January 2026. Mark has a modest pension; both hold substantial pre-tax retirement accounts and a small Roth. Their primary residence—bought in 2002—had become a concentrated source of household wealth after two decades of appreciation in a high-cost metro.

Starting balance sheet (Jan 2026, unchanged):

  • Home: Bought 2002 for $380,000; sale price 2026: $1,150,000.
  • Remaining mortgage: $92,000 at a low fixed rate.
  • 401(k)/Traditional IRA: $1.35 million (pre-tax).
  • Roth IRA: $110,000.
  • Taxable brokerage + cash: $210,000.
  • Pension: $18,000/year.

Their central planning goals remained the same: limit large required minimum distributions (RMDs) beginning at age 73, avoid unintended Medicare IRMAA and Net Investment Income Tax (NIIT) spikes, and leave heirs a cleaner, more tax-efficient inheritance.

Challenge

The couple faced three linked problems:

  • RMD concentration: $1.35M in pre-tax accounts created the potential for sizeable RMDs at age 73 that could push them into higher marginal brackets.
  • Tax timing and liquidity: Roth conversions require paying current income tax. Without liquid taxable assets, conversions can force IRA withdrawals and reduce long-term benefit.
  • Interaction with sale proceeds: Selling a long-held home can generate capital gain; the timing of that gain relative to conversions affects bracket space and surcharges.

Solution

Their advisor team (CPA + CFP) recommended converting home equity into diversified, taxable and tax-advantaged accounts while preserving conversion flexibility:

  1. Use the $500,000 primary-residence exclusion (married filing jointly) to remove most sale gain from ordinary income in the sale year.
  2. Create a 12–24 month taxable cash reserve to cover living costs and conversion taxes.
  3. Execute staged Roth conversions across low-income years before RMDs start—“fill” specific tax brackets without crossing Medicare IRMAA or NIIT thresholds.
  4. Update estate documents and beneficiary designations to reflect a greater Roth share for heirs under current inherited-IRA rules (10-year rule for many non-spouse beneficiaries).

Why this still works in mid-2026: the exclusion remains $250,000/$500,000; RMDs begin at 73; Medicare IRMAA and tax brackets are indexed annually—so deliberate timing, documentation and cash reserves preserve optionality.

Implementation

Step 1 — Pre-sale tax diligence (Q1–Q2 2026)

The couple and their CPA documented cost basis and capital improvements totaling $95,000 (new roof, kitchen refit, energy upgrades). Their calculations:

  • Original purchase: $380,000
  • Improvements: $95,000
  • Adjusted basis: $475,000
  • Sale price: $1,150,000
  • Selling costs (~7%): $80,500
  • Estimated capital gain: $1,150,000 − $80,500 − $475,000 = $594,500

With the $500,000 exclusion, roughly $94,500 remained as long‑term capital gain—small relative to proceeds and importantly leaving ordinary-income room for Roth conversions.

Step 2 — Convert proceeds into liquid flexibility (Q2 2026)

Rather than buying another house immediately, they rented a smaller condo for 24 months to preserve mobility and optionality. Net-proceeds allocation:

  • Pay off mortgage: $92,000
  • 12–24 month cash / short-duration Treasury reserve: $160,000
  • Transition costs: $28,000
  • Taxable brokerage invested for conversion taxes and spending: $650,000

Holding taxable reserves allowed them to pay conversion taxes from non‑retirement funds and avoid withdrawing from pre-tax IRAs during market volatility.

Step 3 — Staged Roth conversions with annual recalibration (2026–2029)

Using updated 2026 IRS inflation adjustments for brackets and Medicare IRMAA thresholds, their CPA modeled conversions to “fill” but not exceed targeted brackets and surcharge breakpoints. Their working schedule (illustrative and revisited annually):

  • 2026: Convert $120,000 (completed June 2026)
  • 2027: Target $120,000
  • 2028: Target $110,000
  • 2029: Target $90,000

Taxes on the 2026 conversion were paid from the taxable brokerage account. The team intentionally avoided timing the conversion in the same calendar year as large deductible events and monitored Medicare IRMAA implication windows (IRMAA uses two-year lookback rules for Part B/D premiums).

Step 4 — Estate coordination and beneficiary work (ongoing)

They updated beneficiary forms and their revocable trust to allocate a larger share of retirement wealth to Roth accounts where appropriate, reflecting the current 10‑year inherited-IRA rule for many non-spouse heirs. That reduces heirs’ future required taxable distributions and simplifies multi-generational tax planning.

Results — June 2026 update

Measured outcomes through June 2026:

  • Home-sale tax treatment: Of the estimated $594,500 gain, $500,000 was excluded; $94,500 reported as long-term capital gain on the 2026 federal return (state treatment depends on domicile).
  • Liquidity created: Net of paying the mortgage and transaction costs, the couple has ~$650,000 invested in taxable accounts and $160,000 in short-duration cash equivalents—sufficient to fund conversion taxes for the planned multi-year schedule.
  • Conversion progress: The 2026 conversion of $120,000 to Roth succeeded; taxes were paid from taxable assets, preserving the Roth principal for long-term growth.
  • Projected RMD impact: Their planner estimates first-decade RMDs reduced by roughly $15,000–$20,000/year versus a no-conversion baseline (sensitivity depends on market returns and life expectancy assumptions).
  • Resilience to volatility: The cash reserve and taxable buffer mean they would avoid forced IRA withdrawals during a 15–25% market drawdown in modeled scenarios—preserving conversion timing and compounding potential.

Why this matters in June 2026

Three contextual developments make this update timely:

  • Indexing matters: For 2026 the IRS adjusted tax brackets, standard deduction and Medicare IRMAA thresholds for inflation. Those adjustments change the annual “headroom” you can safely use for Roth conversions without triggering surcharges.
  • Housing and rates environment: Elevated interest rates and uneven housing-market recovery since 2022 mean many sellers now face more variable after‑tax proceeds. Diligent basis documentation and sale-timing choices can materially affect conversion capacity.
  • Estate-tax and inheritance realities: Under current law, many non-spouse beneficiaries must withdraw inherited IRAs within 10 years. Converting to Roth increases heirs’ potential tax-free wealth during that distribution window.

Lessons Learned

  • Document basis thoroughly. Substantiated capital improvements increased excluded gain; keep receipts, permits and dates.
  • Buy flexibility, not impulse. A temporary rental and liquid reserves create the conversion window that produces long-term benefit.
  • Sequence transactions carefully. Sell, establish reserves, then execute controlled annual conversions—avoid stacking multiple large taxable events into one filing year.
  • Model IRMAA and NIIT implications each year. Because IRMAA uses a two-year lookback and thresholds are indexed annually, conversion planning must consider both current and future premium consequences.
  • Coordinate state taxes. State capital-gains and income-tax rules vary; the sale and conversions should be modeled at both federal and state levels before you close or convert.

Takeaways

  • The primary-residence exclusion remains a powerful, underused way to turn concentrated home equity into convertible, tax-managed capital.
  • Use low-income windows after retirement and before RMDs as Roth-conversion opportunities—stage conversions to avoid spiking Medicare IRMAA, NIIT and marginal rates.
  • Pay conversion taxes from taxable reserves to preserve Roth principal and long-term compounding for you and your heirs.
  • Revisit conversions annually—IRS indexing, health-insurance premium rules and family needs change; what’s optimal one year may not be the next.
  • Think decades: these choices reduce lifetime taxable income and shape a simpler, cleaner inheritance for the next generation.

FAQ

Does the $250,000/$500,000 primary-residence exclusion still apply in 2026?

Yes. The federal exclusion remains $250,000 for single filers and $500,000 for married couples filing jointly. That exclusion applies if you meet the two-out-of-five-years ownership and use tests. State treatment varies, so model state taxes separately.

Will Roth conversions trigger higher Medicare premiums?

Potentially. Medicare Part B and D premiums use an income-based formula (IRMAA) with a lookback; higher AGI in a conversion year can create higher premiums down the line. Planners often stage conversions to “fill” a bracket but avoid breaching IRMAA thresholds. Because the thresholds are indexed, update your plan annually using current IRS figures.

How much cash should I hold after a home sale if I plan conversions?

There’s no one-size-fits-all number, but a practical rule is 12–24 months of living expenses plus estimated conversion-tax reserves. In this case study, Mark and Elena maintained $160,000 in short-duration cash and $650,000 in a taxable account to fund multi-year conversions—sufficient to avoid forced IRA withdrawals during market downturns.

Should I always pay conversion taxes from taxable accounts?

Generally yes—paying taxes from taxable assets preserves Roth principal and enhances the long-term tax-free growth benefit. Paying conversion taxes from IRA funds reduces the conversion’s effectiveness and can create a de facto taxable distribution.

What annual reviews should retirees make after a conversion plan starts?

Each fall review year-to-date income, updated IRS bracket and IRMAA thresholds, projected RMDs, state tax changes, beneficiary designations and spending needs. Recalibrate conversion amounts based on portfolio performance and life changes (health, family events, relocation).

Disclosure: This case study presents a real planning approach adapted to June 2026 conditions. Figures are rounded for clarity. Tax and Medicare outcomes depend on individual facts, state law and possible future legislation. Consult a qualified CPA and CFP for personalized advice.