The Invisible Stretch Between Retirement and Benefits
A 66-year-old retiree stops working, has a sizable traditional IRA, and delays Social Security for a few more years. Her checking account looks thinner than during her career, and her tax return reflects minimal income. That gap between her last paycheck and her first Social Security deposit is one of the most valuable tax windows she will ever see.
The reason matters. Once she turns on Social Security, every dollar pulled from her traditional IRA does two kinds of damage. The dollar gets taxed at her ordinary rate, and it also drags more of her Social Security benefit into the taxable column. Retirement planners call that double hit the tax torpedo. The cleanest way to defuse it is to shrink the traditional IRA before benefits start.
A common retiree forum question goes: I retired at 65, I’m living off cash for a couple of years before claiming, should I be converting to Roth right now? The answer is almost always yes, and the size and pacing of each conversion is where the strategy works or fails.
Why Provisional Income Is the Whole Game
Social Security uses a formula called provisional income to decide how much of your benefit gets taxed. It adds adjusted gross income (AGI), any tax-exempt interest, and half of your Social Security benefits. For a single filer, once that number passes $34,000, up to 85% of benefits become taxable. For married couples filing jointly, the line is $44,000. Those thresholds have not moved since 1984.
Roth withdrawals do not enter the provisional income formula. Traditional IRA withdrawals do. A dollar converted today gets taxed once, at her current low rate, and then never affects her Social Security taxability again. A dollar left in the traditional IRA gets taxed later at a higher rate and pulls her benefit into the torpedo zone.
Her 2026 standard deduction as a single filer is $16,100, and the 12% bracket runs up to $50,400 of taxable income. With almost no other income in a gap year, she can convert roughly $66,000 from traditional to Roth and stay inside the 12% bracket. Rinse and repeat for four years and she has moved a quarter million dollars out of the torpedo’s reach at roughly 12 cents on the dollar.
Delaying benefits sweetens the math. Each year she waits past full retirement age (FRA), her future monthly check grows by about 8%, reaching roughly 24% more by age 70. The gap years do double duty: a bigger lifetime benefit and room to convert at low rates.
The Traps That Quietly Eat the Savings
A clean Roth conversion plan can be undone by three side effects most retirees never see coming.
- IRMAA surcharges. Once on Medicare, premiums are set on a two-year lookback of income. A conversion in 2026 can raise Part B and Part D premiums in 2028. The tiers are cliffs, so one extra dollar of conversion can bump her into a higher surcharge for a full year. Many retirees deliberately cap conversions just below the first IRMAA tier.
- The senior bonus deduction phaseout. For tax years 2025 through 2028, filers age 65 and older get an extra $6,000 deduction on top of the standard deduction. It starts shrinking once modified adjusted gross income passes $75,000 single or $150,000 joint. A conversion that pushes her into the phaseout claws back part of that deduction while raising taxable income.
- Future required minimum distributions. Traditional IRA withdrawals become mandatory at age 73. Converting now shrinks those forced withdrawals later, which keeps her provisional income from drifting back into torpedo territory in her late 70s and 80s.
What to Actually Do With the Window
Spread conversions across each gap year, fill the 12% bracket without spilling into the 22%, and watch the MAGI lines that matter for income-related monthly adjusted amount (IRMAA) and the senior deduction. A CPA who can run a multi-year projection is worth the fee, because the interactions are where retirees lose money quietly.
The mistake hardest to undo is claiming Social Security first and converting second. Once benefits are flowing, every conversion dollar drags more of those benefits into the taxable column, and the cheap window has closed. Convert during the quiet years, and the torpedo never has a target.
Every retiree’s mix of accounts, health coverage, and state taxes shifts the right answer. The structure above is the playbook. The dollar amounts depend on individual circumstances, ideally modeled with someone who can project the full picture before the first conversion.
Top Gaining Stocks
Top Losing Stocks