Roth Conversion + State Tax: Wait Until You Move?

Margaret, 64, single, lives in San Jose, California with a $1.1M traditional IRA and plans to retire next year and move to Naples, Florida. Her advisor mapped out $200,000-per-year Roth conversions to drain the IRA before RMDs hit. The federal tax is the same whether she converts in California or Florida. The state tax is not. Converting $200,000 while she’s still a California resident costs her about $18,600 in state income tax (roughly a 9.3% marginal rate on that block of income). Converting the identical $200,000 the year after she’s a bona fide Florida resident costs her $0 in state tax. Same federal bill, same Roth balance — one timing choice, $18,600 saved.

That is the entire decision in this article: a Roth conversion is taxed by the state you live in on the day you convert. Not where you earned the money decades ago. Not where the IRA custodian sits. Where you reside on the conversion date. If your retirement plan includes a move across state lines, the order of operations — convert first or move first — can be worth tens of thousands of dollars.

The rule everyone forgets: conversions are state income

A Roth conversion moves money from a pre-tax traditional IRA or 401(k) into a Roth account. The converted amount is fully taxable ordinary income in the year of the conversion (per IRC §408A(d)(3)). The federal government taxes it on your §1 brackets. And almost every state that has an income tax treats it exactly like any other ordinary income — a wage, a pension check, a regular IRA distribution.

The conversion deadline is December 31 of the tax year — not April 15 like an IRA contribution. So your state of residence is locked to the calendar year in which the conversion clears. Convert on December 20 while domiciled in California, and California taxes it. Convert on January 5 of the next year after you’ve genuinely relocated to Florida, and California gets nothing (subject to the residency rules below).

Everyone models the federal bracket-fill carefully. State tax is the cost that quietly doubles the bill in high-tax states and most people never run the number until it shows up on the state return.

The 9 states that tax a conversion at $0

Nine states levy no broad personal income tax, so a Roth conversion done as a resident there carries zero state cost:

• Alaska, Florida, Nevada, South Dakota, Texas, Washington, Wyoming — no personal income tax at all.
• New Hampshire — historically taxed only interest and dividends, and that tax has been phased out. It never taxed IRA distributions or conversions.
• Tennessee — the old Hall tax on interest and dividends was fully repealed (gone since 2021). It never reached retirement distributions.

Critically, New Hampshire and Tennessee do not tax IRA-to-Roth conversions. A conversion is a retirement-account distribution, and neither state’s narrow (now-defunct) tax on investment income touched distributions. For conversion-timing purposes, treat all nine as $0-state-tax destinations.

One caveat for Washington: it has no income tax, but it does levy a 7% excise tax on long-term capital gains above $250,000. That tax applies to capital gains, not to ordinary income, so it does not reach a Roth conversion. A conversion in Washington is still $0 state tax.

The decision tree: which direction are you moving?

The timing call flips entirely depending on the direction of your relocation. Find your situation:

The reason the no-tax-to-high-tax case is so urgent: once you become a California resident, every remaining pre-tax dollar you eventually convert — or that comes out as an RMD — is exposed to up to 13.3%. The only window to convert at $0 state tax is before you establish residency.

Worked example: $200K conversion, California vs. Florida

Back to Margaret. She wants to convert $200,000 this year. Here’s the side-by-side, holding the federal tax constant (both scenarios use the same 2026 single brackets):

The federal column is identical, so the entire savings is the avoided California tax. If Margaret runs the same $200,000 conversion for several years — say four years to drain a $1.1M IRA below the RMD danger zone — and she can shift even three of those years to after the Florida move, she keeps roughly $55,000+ that California would otherwise have collected.

New York runs smaller but still material. A $200,000 conversion by a single filer lands largely in New York’s 5.85% marginal bracket (taxable income $27,900–$161,550), costing roughly $11,000–$11,700 in state tax — and an NYC resident adds up to 3.876% on top. Move to Florida first, and all of it disappears.

The reverse play: convert before you move to California

Flip the facts. Raymond, 66, married filing jointly, lives in Dallas, Texas with a $900,000 traditional IRA. He and his spouse plan to move to San Diego in two years to be near grandchildren. Texas has no income tax; California has the highest in the country.

For Raymond, every conversion dollar he does not complete before the California move gets exposed to California tax for the rest of his life — on conversions or on RMDs. The lever is to accelerate: fill the federal brackets aggressively in these last two Texas years (using the 2026 MFJ brackets, the 24% bracket runs to $394,600 of taxable income, the 22% bracket to $206,700). Converting $200,000–$300,000 per year now, at $0 state cost, beats converting the same dollars later at California’s 9.3%–13.3% marginal rates. The federal cost is the same; the Texas timing makes the state cost zero.

What most people miss: a paper move doesn’t work

The strategy lives or dies on one word: residency. High-tax states do not let you avoid their tax by renting a mailbox in Florida. California (Franchise Tax Board) and New York (Department of Taxation and Finance) are the two most aggressive residency auditors in the country, and a large Roth conversion in the year of a claimed move is exactly the kind of event that draws scrutiny.

Both states apply two overlapping concepts:

1. Statutory residency (the day count). Spend 183+ days in the state and maintain a home there, and you can be taxed as a resident regardless of where you claim domicile. To be safe, you want to be physically present in the new state for the bulk of the conversion year.
2. Domicile (your true home). This is the harder, facts-and-circumstances test: where your driver’s license is issued, where you’re registered to vote, where your doctors and bank are, where your family and belongings live, where you spend holidays. A domicile change requires actually abandoning the old state and establishing the new one.

The practical sequence: complete the move, change the licenses and registrations, sell or genuinely vacate the old-state home, then convert in a year you can clearly demonstrate residency in the new state. Watch for source-state and part-year rules — in a part-year move year, the high-tax state can tax income attributable to your residency period. Cleanest outcome: convert in a full year of new-state residency, not the transition year. The few hours of documentation are cheap insurance against an $18,600 reassessment plus penalties.

How the state lever stacks on the federal math

State timing does not replace the federal bracket-fill decision — it layers on top of it. The federal question is always “how much to convert this year to fill a target bracket without spilling into the next one or triggering IRMAA.” The state question is “which year should those conversions happen relative to my move.” Three things to reconcile:

• IRMAA timing. Medicare surcharges look back two years. A large conversion at 64 raises 2026 MAGI that drives 2028 Part B/D premiums. Coordinate the move year and the conversion year so you don’t stack a high-tax-state conversion and an IRMAA spike in the same plan.
• The 5-year clock. Each conversion starts its own 5-year clock for penalty-free access to converted principal (you must wait 5 years per conversion unless you’re 59½+). Moving to dodge state tax shouldn’t push a conversion past the age you need the money.
• RMD pressure. If you’re born 1951–1959, RMDs start at 73 (SECURE 2.0 §107). The bigger the unconverted IRA at 73, the larger the forced distribution — taxed in whatever state you then live in. Delaying conversions for a move only helps if the move actually happens before RMDs force your hand.

Key takeaways

• A Roth conversion is taxed by the state you reside in on the conversion date (deadline Dec 31). The federal tax is the same everywhere; the state tax is the variable you control with timing.
• Moving high-tax → no-tax (e.g., California → Florida)? Delay conversions until you’re a bona fide resident. A $200,000 conversion saves ~$18,600 in California or ~$11,700 in New York.
• Moving no-tax → high-tax (e.g., Texas → California)? Accelerate — convert everything you can at $0 state tax before you establish residency in the high-tax state.
• The 9 no-tax states are AK, FL, NV, NH, SD, TN, TX, WA, WY. New Hampshire and Tennessee do not tax IRA-to-Roth conversions; Washington’s 7% gains tax doesn’t touch conversions either.
• The move must be genuine. California and New York audit residency hard — satisfy the 183-day count and the domicile test, change licenses/registration, and convert in a full year of new-state residency, not the transition year.
• Layer the state-timing decision on top of the federal bracket-fill amount, and coordinate it with IRMAA’s 2-year lookback, each conversion’s 5-year clock, and your RMD start age (73 if born 1951–1959, per SECURE 2.0 §107).