Roth Conversions Before Social Security: The Gap-Year Window

If you retire before claiming Social Security — even a few years early — you're sitting on one of the most underused tax-planning windows in retirement. Your income drops sharply. Your tax brackets are nearly empty. And every dollar you leave sitting in a traditional IRA is a dollar that will be subject to ordinary income tax when you withdraw it — including the years when your Social Security benefit and required minimum distributions stack on top of each other, potentially pushing you into a higher bracket than you're in today.

The strategy is called gap-year Roth conversions: systematically converting traditional IRA or 401(k) balances to Roth during the years between your last paycheck and your first Social Security check. The calculator below models your specific window.

Why the gap years matter so much

When Social Security starts, it changes your entire income picture. Even if your monthly benefit is $2,500 — $30,000 per year — up to $25,500 of it becomes subject to federal income tax if your other income pushes you past the provisional income thresholds.¹ Those thresholds — $25,000 for single filers, $32,000 for married filing jointly — have never been adjusted for inflation since they were set in 1983. In practice, most retirees with any meaningful savings end up with 50–85% of their Social Security benefit taxed as ordinary income.

On top of that, required minimum distributions (RMDs) begin at age 73 if you were born before 1960, or age 75 if born 1960 or later.² If you arrive at RMD age with a large untouched IRA, those forced withdrawals will stack on top of your Social Security income — potentially moving you into the 22% or 24% bracket for the rest of your life.

The Roth conversion window solves this in advance. Roth distributions in retirement are not included in your gross income, do not count toward provisional income, and do not trigger IRMAA surcharges. Every dollar you move to Roth before SS starts is a dollar that never contributes to the problem.

How much can you convert each year?

The arithmetic is straightforward. In a gap year with no wages and no Social Security income, your taxable income is just your other income (pension, dividends, portfolio withdrawals) minus your deductions. The question is: how much Roth conversion can you layer on top of that before hitting the next bracket?

For 2026, the relevant thresholds are:³

• Top of 12% bracket: $50,400 taxable income (single) / $100,800 (MFJ)
• Top of 22% bracket: $105,700 (single) / $211,400 (MFJ)
• 2026 standard deduction: $16,100 (single) / $32,200 (MFJ) — plus $2,050/$1,650 per person age 65+
• OBBBA Senior Bonus Deduction (2025–2028): $6,000 per person age 65+, phasing out 6% above $75,000 MAGI (single) / $150,000 (MFJ)⁴

A married couple where both spouses are 65+ has total 2026 deductions of approximately $47,500 before any MAGI phaseout ($32,200 + $3,300 + $12,000). That means taxable income of zero until their AGI reaches $47,500 — and they can convert up to $148,300 of gross income before their first dollar hits the 22% bracket. Against $20,000 of other income, that leaves $128,300 per year of Roth conversion capacity at 12% or lower.

Worked example: married couple, 63, planning to claim at 70

Paul and Lisa are 63, both retired. They have $750,000 in traditional IRAs and expect $4,200/month combined Social Security at age 70 — a 7-year gap. Their other income: $25,000 a year in dividends and taxable bond interest. Neither is 65 yet, but they will be 65 by year 3 of the window.

Without conversions: At 70 they claim Social Security ($50,400/year). At 73 — three years later — RMDs kick in. First-year RMD on $750,000: roughly $28,300. Their provisional income: $25,000 + $28,300 + $25,200 (half of SS) = $78,500. Well above the $44,000 joint upper threshold — 85% of their SS ($42,840) is fully taxable. Taxable income: $25,000 + $28,300 + $42,840 minus ~$47,500 deductions = $48,640. Federal tax: roughly $5,800. And this repeats every year, growing as RMDs rise.

With gap-year conversions: Over 7 years they convert approximately $75,000–$90,000 per year — staying in the 12%–15% effective range with 65+ deductions — reducing the IRA to roughly $150,000. First-year RMD on $150,000: $5,660. Provisional income drops to $25,000 + $5,660 + $25,200 = $55,860. Taxable SS falls from $42,840 to roughly $10,000. Taxable income: roughly $6,000. Federal tax near zero. Annual savings at that point: $5,800+. Over a decade, net of the conversion taxes paid during the 7-year window, the couple can save $30,000–$60,000 in federal taxes — and that figure grows as RMDs compound upward without conversions.

What if my gap is short — or I've already claimed?

A 2–3 year gap still creates meaningful opportunity, especially with large IRA balances. The math changes if your other income is high enough to already push you into the 22% bracket during the gap — in that case, conversions at 22% today only make sense if you expect to be in the 24%+ bracket later (possible with large RMDs + SS).

If you've already started Social Security, gap-year conversions aren't available — but voluntary suspension (if you're between FRA and 70) can restart delayed credits and may justify a short suspension window during which conversions make sense at lower rates. This is the "do-over" strategy covered in our do-over guide.

When the window doesn't help as much

• Large pension income: If you have a $60,000/year pension, your gap-year income is already high enough that conversion room is limited — and your post-SS bracket may be only marginally higher than your conversion bracket. Run the numbers before assuming conversions help.
• Very short gap (under 2 years): The total conversion capacity is limited. It may still be worth doing, but the lifetime savings are smaller.
• Conversions require cash from the IRA: If you need to use the converted funds to pay the tax bill — rather than paying taxes from a separate taxable account — the effective cost is higher. Ideally you pay conversion taxes from cash or non-IRA funds.
• State income tax: Some states tax Roth conversions as ordinary income. The federal math may look great while the state tax adds 5–10% to the cost. Check your state's treatment before converting aggressively.

Sources

1. IRS Publication 915 — Social Security and Equivalent Railroad Retirement Benefits: IRC § 86 provisional income formula, thresholds ($25,000/$34,000 single; $32,000/$44,000 MFJ), established 1983/1993, never inflation-indexed.
2. IRS Rev. Proc. 2025-32 — 2026 tax parameters including brackets, standard deductions, and additional 65+ deduction amounts. SECURE 2.0 § 107: RMD age 73 for those born 1951–1959; § 107 as modified: RMD age 75 for those born 1960 or later.
3. Tax Foundation — 2026 Federal Income Tax Brackets: single (10%: $0–$12,400; 12%: $12,401–$50,400; 22%: $50,401–$105,700) and MFJ (10%: $0–$24,800; 12%: $24,801–$100,800; 22%: $100,801–$211,400). IRS Rev. Proc. 2025-32.
4. IRS — OBBBA Tax Deductions for Seniors: new $6,000 per-person Senior Bonus Deduction for age 65+, effective 2025–2028, phases out 6% over $75,000 (single) / $150,000 (MFJ) MAGI. Available to both itemizers and standard deduction filers.
5. SSA — Medicare IRMAA 2026: first-tier threshold $109,000 (single) / $218,000 (MFJ); surcharge $418/year Part B. SSA POMS HI 01101.020.

Tax brackets, standard deductions, and OBBBA Senior Bonus Deduction per IRS Rev. Proc. 2025-32. Provisional income thresholds per IRC § 86 (1983/1993, not inflation-indexed). RMD ages per SECURE 2.0 §107. Uniform Lifetime Table factors from IRS Publication 590-B. 2026 IRMAA thresholds per SSA. Values verified April 2026.