Part 1 — Direct Answer

Arizona taxes retirement income at a flat 2.5% rate — one of the lowest state income tax rates in the nation. However, not all retirement income is taxable in Arizona. Social Security benefits are completely exempt from Arizona income tax. Roth IRA withdrawals are not taxed. Traditional IRA, 401(k), and pension distributions are taxed as ordinary income at the flat 2.5% rate. Arizona's favorable tax treatment makes it one of the better states for retirees, particularly those who have built up significant Roth assets.

Part 2 — Detailed Explanation

Arizona's income tax structure changed significantly in recent years. The state moved from a graduated bracket system to a flat 2.5% rate, effective for tax years beginning in 2023. Every dollar of taxable income above the standard deduction is now taxed at the same rate regardless of income level. For retirees, this simplifies planning considerably — there are no brackets to stay under, no marginal rate cliffs to manage at the state level.

What Arizona taxes and what it doesn't tax on retirement income breaks down as follows. Social Security benefits are fully exempt from Arizona income tax, regardless of how much of your benefit is federally taxable. Arizona does not follow the federal formula that taxes up to 85% of benefits at the federal level — at the state level, your Social Security check is entirely untouched. This is a significant benefit for Arizona retirees compared to states that partially or fully tax Social Security.

Roth IRA withdrawals follow federal treatment. Since qualified Roth distributions are not taxable at the federal level, they are also not taxable in Arizona. This makes Roth assets doubly valuable in Arizona — every dollar in Roth escapes both federal and state income tax on qualified distributions.

Traditional IRA and 401(k) withdrawals are taxed as ordinary income in Arizona at the flat 2.5% rate. Pension income from private-sector employers is also taxable. However, Arizona provides specific exemptions for certain government pensions. Military retirement pay is fully exempt from Arizona income tax. Federal government employee pensions (from federal civilian employment) receive an exemption of up to $2,500 per year. Arizona state and local government pensions are also partially exempt. If you or your spouse receive any of these pension types, the specific exemption amounts should be confirmed with a tax professional as they can change with legislation.

Investment income — dividends, capital gains, interest — is taxable in Arizona at the same 2.5% flat rate applied to earned income. Long-term capital gains do not receive preferential state treatment in Arizona the way they do at the federal level. Every dollar of capital gain is taxed at 2.5% at the state level regardless of how long you held the asset. This makes tax-loss harvesting in taxable accounts slightly more valuable for Arizona residents, as losses offset gains that would otherwise be taxed at both federal and state rates.

Arizona's standard deduction for 2025 is $14,600 for single filers and $29,200 for married filing jointly — matching the federal standard deduction. Arizona also conforms to many federal deductions, simplifying the state return for most retirees.

One important nuance: Arizona's conformity to federal tax law is updated periodically and does not always match federal law immediately. Changes from federal legislation — including SECURE 2.0 Act provisions — may take one or more years to be incorporated into Arizona law. Working with an Enrolled Agent who handles both federal and Arizona returns ensures that any conformity gaps are identified and addressed in your filing.

Part 3 — What This Means for You

For a married couple with $3M in assets — $2M in a traditional IRA, $500K in a Roth IRA, and $500K in taxable brokerage — the Arizona tax picture is actually quite manageable. Social Security is untaxed. Roth withdrawals are untaxed. Only the traditional IRA distributions and capital gains from the taxable account face Arizona's 2.5% rate.

A couple drawing $150,000 per year from their traditional IRA in retirement would owe approximately $3,750 in Arizona income tax on that income. That is a remarkably low state tax burden compared to California, where the same income would face a state tax rate of 9.3% or higher. Arizona's tax structure genuinely rewards retirees who have diversified their account types — particularly those who have built Roth assets through conversions.

The most important planning implication is that Arizona's 2.5% rate makes Roth conversions particularly efficient. Paying 2.5% today on converted amounts to permanently eliminate Arizona state tax on future distributions and growth is a compelling trade-off, especially for large pre-tax balances.

Part 4 — Common Mistakes and Misconceptions

• The most common mistake is assuming Arizona taxes all retirement income at the same rate as earned income. Many pre-retirees are surprised to learn Social Security is fully exempt and Roth withdrawals face no state tax — leading them to underestimate how tax-efficient an Arizona retirement can be.
• The second mistake is ignoring the military and government pension exemptions. Retirees with qualifying pension income who don't claim their exemption leave money on the table every year.
• The third mistake is not accounting for Arizona's conformity lag. When federal tax law changes, Arizona may not immediately conform — leading to situations where Arizona taxable income differs from federal taxable income. An advisor who files both returns catches this automatically.