Traditional IRA vs Roth IRA: Complete Comparison

Choosing between a Traditional IRA and a Roth IRA is one of the most consequential decisions in retirement planning. Both are individual retirement accounts with tax advantages — but the tax benefit comes at different times, and the right choice depends on your income today, your expected income in retirement, and your state of residence. The IRS provides an official comparison of Traditional and Roth IRAs including deduction limits and eligibility rules.

How They Work

A Traditional IRA gives you a tax deduction when you contribute. Your money grows tax-deferred, and you pay income tax on withdrawals in retirement. Contributions may be fully deductible, partially deductible, or non-deductible depending on your income and whether you have a workplace plan.

A Roth IRA takes after-tax dollars. You get no deduction today, but all growth and qualified withdrawals are completely tax-free. There’s no tax on withdrawals after age 59½ (assuming the account has been open at least 5 years), and there are no Required Minimum Distributions during your lifetime.

Contribution Limits (2025)

Both accounts share a combined annual contribution limit:

• Under 50: $7,000
• Age 50+: $8,000 (catch-up contribution)

You can split contributions between Traditional and Roth IRAs, but the total across both cannot exceed the limit.

Income Limits

Roth IRA income limits (2025):

• Single: Full contribution up to $150,000 MAGI; phase-out to $165,000
• Married filing jointly: Full contribution up to $236,000 MAGI; phase-out to $246,000

Above these limits, you cannot contribute directly to a Roth IRA (though the backdoor Roth strategy may still work).

Traditional IRA deduction limits: If you or your spouse has a workplace retirement plan (401(k), 403(b)), the deductibility of Traditional IRA contributions phases out at certain income levels. Without a workplace plan, the full deduction is available regardless of income.

The Core Decision Framework

Choose Traditional IRA When:

1. Your current tax rate is higher than your expected retirement rate. If you’re in the 24% bracket now and expect to be in the 12% bracket in retirement, the Traditional IRA saves you 12 cents on every dollar contributed.

2. You need the tax deduction now. The upfront deduction reduces your current-year tax bill, freeing cash flow for other goals.

3. You’re in peak earning years. Ages 45–60 often represent the highest income — and highest marginal rates — of your career. The deduction is worth the most here.

Choose Roth IRA When:

1. Your current tax rate is lower than your expected retirement rate. Early career, between jobs, or in a gap year before Social Security — these are windows where Roth contributions or conversions are most efficient.

2. You want tax-free income in retirement. Roth withdrawals don’t count toward the taxation of Social Security benefits, don’t trigger IRMAA Medicare surcharges, and don’t increase your state income tax.

3. You want flexibility. Roth IRA contributions (not earnings) can be withdrawn at any time without penalty or tax. This makes the Roth a more flexible vehicle than the Traditional IRA.

4. You believe tax rates will rise. If you expect future tax legislation to push rates higher, locking in today’s rate through the Roth is a hedge.

Required Minimum Distributions

Traditional IRAs require minimum withdrawals starting at age 73 (under current law). The amount is calculated from your account balance and an IRS life expectancy table. RMDs are taxed as ordinary income and can push you into higher brackets, trigger Social Security taxation, and cause IRMAA surcharges.

Roth IRAs have no RMDs during the original owner’s lifetime. This means your Roth can continue compounding tax-free for as long as you live, making it the most efficient account to leave to heirs (though beneficiaries will have RMD obligations under the 10-year rule).

The Tax Diversification Argument

Many planners recommend contributing to both account types over your career. This gives you tax diversification — the ability to pull from taxable, tax-deferred, and tax-free buckets in retirement to manage your effective rate year by year.

In low-income years, withdraw from the Traditional IRA to fill lower brackets. In high-income years, use the Roth to avoid pushing into higher brackets. This flexibility is worth more than optimizing for a single account type.

State Tax Considerations

State taxes can tilt the decision:

• No income tax states (TX, FL, NV, WA, TN, WY, SD, AK, NH): The Traditional IRA deduction is only worth the federal rate. If you plan to retire in one of these states, Traditional contributions during high-earning years in a high-tax state capture both federal and state deductions.

• States that tax retirement income differently: Some states partially or fully exempt retirement account withdrawals, Social Security, or pension income. Check your state’s rules — they can change the math significantly.

Example: Sarah, Age 32, Software Engineer

Sarah earns $95,000 in Colorado (state tax ~4.4%). She contributes to her company 401(k) and wants to know whether her IRA should be Traditional or Roth.

• Current federal marginal rate: 22%
• Combined federal + state: ~26.4%
• Expected retirement rate (at $50,000 income in today’s dollars): 12% federal + 4.4% state = ~16.4%

The 10-percentage-point spread favors the Traditional IRA on pure math. But Sarah is 32 — she has 30+ years of tax-free compounding in a Roth ahead of her. If she expects tax rates to rise even modestly, the Roth becomes competitive. And the Roth’s lack of RMDs gives her more control in her 70s.

A reasonable strategy: max the 401(k) for the Traditional deduction, then fund a Roth IRA for tax diversification.

Conversion Between Accounts

You can convert Traditional IRA funds to a Roth IRA at any time. You’ll pay income tax on the converted amount, but all future growth becomes tax-free. Roth conversions are particularly powerful in low-income years — see our Roth Conversion Strategy guide for a detailed breakdown.

How Cinderfi Helps

Cinderfi models both Traditional and Roth IRA contributions side by side in your retirement projection. It calculates your effective marginal rate including federal tax, state tax for all 50 states, Social Security taxation, and IRMAA surcharges — so you can see the true cost of each dollar in each account type. The scenario comparison tool lets you run Traditional-heavy vs Roth-heavy strategies against each other to find your optimal split.

Model your IRA strategy — try Cinderfi free.