A 68-year-old single retiree with a seven-figure traditional IRA did everything the retirement blogs told him to do. Before required minimum distributions kick in, he ran a bracket-fill Roth conversion of $80,000, moving his modified adjusted gross income from roughly $70,000 to about $150,000. But he didn’t expect the conversion to wipe out the entire new bonus deduction for taxpayers 65 and older.
This is a very 2026 problem. The One Big Beautiful Bill created a temporary bonus deduction on top of the long-standing extras seniors already receive, and it phases out with income. Retirees who are financially literate, and doing the right things, are running into a rule that did not exist three years ago.
The bonus senior deduction is real, valuable, and stackable with the regular standard deduction plus the existing additional standard deduction for those 65 and older. It is available whether you itemize or not.
It also has a phase-out. Above the MAGI threshold, the deduction shrinks by 6 cents for every additional dollar of income. For a single filer, the deduction begins fading at around $75,000 of MAGI and is fully gone by roughly $175,000. The retiree in this scenario pushed his MAGI from below the threshold to a level where the deduction is essentially extinguished. On a $80,000 conversion, roughly $6,000 of deduction value evaporated in addition to the federal tax bill on the conversion itself.
MAGI sets the marginal federal bracket, which for tax year 2026 tops out at 37% above $640,600 for single filers and steps down through 24% above $105,700 and 22% above $50,400. It determines the IRMAA tier that will hit two years out. And now it controls how much of the senior bonus deduction survives. The old advice, fill the 22% or 24% bracket to the top, could cost you the bonus.
Two Strategic Paths
Path one: Size the conversion to respect the phase-out rather than the bracket. Instead of converting to the top of the 22% or 24% bracket, cap the conversion where MAGI stays under the single-filer threshold or only partially into the phase-out band. This converts less per year but preserves the deduction, keeps IRMAA lower, and can be repeated. Spreading a large conversion across three or four years is usually more efficient when a phase-out cliff is in play.
Path two: For retirees close to the sunset year of the provision, push conversions into the years after the bonus deduction is scheduled to disappear. When the deduction is gone anyway, there is nothing left to lose to a phase-out, and RMD math or bracket movement can drive the schedule instead. This path only makes sense if RMDs are still a few years out and current-bracket space is not being wasted.
Qualified charitable distributions from an IRA count against RMDs but stay out of MAGI. Married filers with two qualifying spouses have twice the deduction at stake and a higher combined threshold, so coordination between spouses becomes its own planning exercise.
What to Do Before December 31
- Model MAGI, not just the bracket. Before authorizing any conversion this year, project MAGI including Social Security, pensions, dividends, and the conversion itself. If MAGI crosses the senior deduction phase-out zone, shrink the conversion until it fits, or split it across two tax years.
- Remember the two-year IRMAA echo. A conversion that looks fine in isolation can trigger higher Medicare Part B and Part D premiums two calendar years later. Budget for that bill when sizing this year’s conversion.
Contact [email protected] for any questions or corrections.
Top Gaining Stocks
Top Losing Stocks