The tax mechanics, plainly
You contribute pre-tax (assuming you're eligible for the deduction). The contribution reduces taxable income now.
Money grows without annual tax. No dividend tax, no capital-gains tax, no interest tax — just pure compounding.
Withdraw in retirement, pay ordinary income tax on the full amount. That's the deferral closing.
Traditional vs Roth — the only question that matters
Will your marginal tax rate in retirement be higher or lower than today?
Lower in retirement: Traditional wins. Deduct at high rate, withdraw at low rate.
Higher in retirement: Roth wins. Pay low rate now, never pay again.
Most people in peak earning years bet on lower retirement taxes — that's why Traditional is the workhorse for high earners.
The RMD trap
RMDs start at 73 and rise as a percentage with age — by 90, you're required to withdraw ~9% per year.
Combined with Social Security, this can push you into higher tax brackets in late retirement than you were in mid-retirement.
Mitigation: do Roth conversions in low-tax years (early retirement) to drain the Traditional IRA before RMDs hit hard.
Who can deduct, who cannot
No workplace plan: full deduction at any income.
You have a workplace plan: phased out at $89–109k single, $146–166k joint (2026).
Your spouse has a workplace plan, you don't: phased out at $230–240k joint.
Above phase-out: non-deductible Traditional IRA still allowed — useful as a backdoor Roth conduit.
Common Traditional IRA mistakes
- Skipping the deduction in a year you qualified for it.
- Not coordinating with workplace 401(k) for the active-participant rule.
- Missing an RMD and triggering the 25% penalty.
- Doing a Roth conversion in a peak-tax year.
- Forgetting the pro-rata rule on backdoor Roths.