The low-income year that turns into a tax-free retirement
Meet Carol. She's 62, just retired, and won't start Social Security until 70. For the next eight years her only income is a small pension, and her 2026 taxable income lands at roughly $28,000 after the $16,100 standard deduction for a single filer. She's sitting in the 12% bracket with a giant $852,000 Traditional IRA that the IRS will eventually tax at far higher rates once required withdrawals kick in at 73.
Here's what most people miss in a year like this. The 12% bracket for a single filer runs up to about $50,400 of taxable income in 2026. Carol has roughly $22,400 of unused space inside that bracket before the next dollar gets taxed at 22%. That gap is the opportunity, and it disappears the moment Social Security and required distributions start stacking income on top of each other.
So she converts $22,400 from her Traditional IRA to a Roth this year. The tax bill: $2,688 (12% of $22,400). That's it. The money moves into the Roth, grows untouched, and every dollar of future growth and withdrawal comes out tax-free. No required distributions on it ever, and nothing it earns counts as income later.
Now run the math forward. If that $22,400 grows at 7% for the 20 years until she's 82, it becomes roughly $86,700 inside the Roth. Had it stayed in the Traditional IRA, every dollar of that $86,700 would be taxable on withdrawal. Pulled out in a 22% retirement bracket, the tax would run past $19,000. She paid $2,688 today to erase a $19,000 bill later. That's the trade the conversion buys.
And she doesn't do it once. Eight low-income years before Social Security and required minimum distributions begin, each one filling the 12% bracket to the top, can move $150,000 or more into the Roth at one of the lowest tax rates she'll ever pay. Total tax across those eight years: under $18,000. The same dollars, left in the Traditional IRA and withdrawn later on top of Social Security and pension income, could easily land in the 22% or 24% bracket and trigger tax on her Social Security benefits at the same time.
This is the quiet logic of bracket-filling. You aren't avoiding the tax. You're choosing when to pay it, and paying it in the cheapest years of your life instead of the most expensive. The window is narrow, usually the handful of years between retiring and the day required distributions force your hand, and most people let it pass without doing the arithmetic. The calculator above does Carol's math with your own numbers: enter your current taxable income, the amount you're thinking of converting, and the rate you expect in retirement, and it shows the tax due now against the tax-free balance you're buying for later.