A traditional IRA contribution and a traditional IRA deduction are not always the same amount. Workplace-plan coverage, filing status and modified AGI can limit or eliminate the deduction even when a contribution is permitted.
Formula and decision rule
Simplified federal tax reduction = deductible IRA amount × marginal federal rate. The key input is the amount actually deductible under current IRS rules, not automatically the full contribution. Nondeductible contributions require proper tax-basis records.
Worked example
If $5,000 is confirmed deductible and the taxpayer is in a 22% marginal federal bracket, the simplified current federal reduction is $5,000 × 22% = $1,100. This excludes state tax, credit interactions and any difference between marginal and effective rate.
Eligibility workflow
- Confirm the contribution is within the applicable current limit.
- Identify whether the taxpayer or spouse is covered by a workplace retirement plan.
- Use filing status and modified AGI with the current IRS deduction table.
- Enter only the deductible amount in a tax estimate.
- Keep Form 8606 records when required for nondeductible basis.
Contribution timing
Contribution deadlines and tax-year designations matter. Confirm the tax year with the custodian and current IRS filing instructions instead of relying on a generic calendar assumption.
Use the calculator
The Income Tax Calculator labels its IRA field “deductible amount” so a nondeductible contribution is not silently treated as reducing AGI.
Primary sources
Frequently asked questions
Does a traditional IRA contribution reduce FICA?
No. An IRA contribution outside payroll does not reduce Social Security or Medicare wages.
Why does BriskCalc not calculate the phase-out automatically?
Deductibility depends on details beyond a single income input. The calculator requires a verified deductible amount rather than implying eligibility.
Change log
Published August 28, 2026 with an eligibility-first workflow and a clear distinction between contribution and deduction.