Updated July 28, 2026. Quick answer: In the year you move you are generally a part-year resident of both states, and each taxes the income attributable to its own period. For a conversion — a single event on a single date — that usually means residency at the moment of conversion decides it.
Why a conversion is different from salary
Salary earned across a move is naturally divided by where the work happened. A conversion is a single event on a single day. There is no natural apportionment, so the question collapses to where you were resident when it happened.
Which makes the date genuinely consequential in a way it is not for most income.
Residency is determined on facts, not on a moving date. Selling the old home, registering to vote, changing licences and actually being physically present all matter. A conversion executed days after a nominal move, with the old home unsold, is exactly what a departure-state audit looks for — and high-tax states do look.
Practical sequence
- Establish residency properly and document it.
- Then convert — not the other way round.
- Expect to file part-year returns in both states for that year.
Whether the destination state taxes conversions at all is the first thing to check: see the state-by-state treatment, where 24 of 51 land in buckets the common shortcut gets wrong.
Sources
IRC §408A (Roth IRAs); IRC §408A(d)(3); IRC §402(c)(11) (inherited plan amounts); IRC §170 (charitable deduction); IRC §172 (net operating losses); SECURE Act (2019) and final RMD regulations published 19 July 2024. Cross-checked July 2026 against professional analyses. Indexed thresholds, aid formulas and state Medicaid rules are described rather than asserted — they change annually and by state.
This states what the cited authority says. It is not tax advice.