Formula and method
The eligible contribution is limited by compensation, the 2026 IRA cap, other IRA contributions and the Roth MAGI phaseout. Within the phaseout, apply the IRS reduced-limit method, rounding upward to the next $10 with a $200 floor before the remaining overall IRA limit. Project annual deposits at year-end.
Worked example
At age 35 with sufficient compensation, $160,500 single-filer MAGI is halfway through the 2026 phaseout. The modeled Roth limit is $3,750 before other IRA contributions. At $168,000 MAGI, the direct-contribution limit is zero.