Updated July 28, 2026. Quick answer: No. New Hampshire has no state income tax, so converting to a Roth costs you nothing at the state level. Only the federal bill applies.
Why a conversion is a different question from a withdrawal
Almost every state summary answers “how does New Hampshire tax retirement income?” That is a question about distributions. A Roth conversion is not a distribution in the ordinary sense — it is a voluntary election to recognise income now in exchange for tax-free growth later. Whether a state’s retirement exclusion reaches that election is a separate question, and it is the one that decides your bill.
This is the simplest case on the map. New Hampshire levies no tax on ordinary income, so the entire question of whether a retirement exclusion covers a conversion never arises. Your conversion is a federal-only event here.
The planning consequence is the opposite of what people expect: because the state adds nothing, the timing question in New Hampshire is purely federal — bracket, IRMAA, and the tax you pay from outside the account.
What New Hampshire does with the converted amount
State income tax: none (Interest & Dividends Tax repealed for taxable periods beginning after 12/31/2024)
How New Hampshire treats IRA and plan income: Not taxed. NH never taxed wages or retirement distributions; with the I&D tax repeal effective 1/1/2025 (HB 2, 2023 session), NH imposes no individual income tax at all.
| Conversion | State tax in New Hampshire |
|---|---|
| $50,000 | $0 |
| $100,000 | $0 |
| $250,000 | $0 |
What to ask a preparer about New Hampshire
Nothing to ask at the state level. Spend the question on federal timing.
Converting around a move
Converting after establishing residency in New Hampshire is the whole play. People moving here from a taxing state sometimes convert before the move and pay a state bill they could have avoided entirely by waiting.
Four separate taxes change when you move, not one: income tax on withdrawals, treatment of Social Security, estate tax, and inheritance tax. A state that looks good on conversions can be worse on the other three.
The state bill is the smaller half
Whatever New Hampshire does, the conversion is federal ordinary income first. The federal bracket you land in, and whether the conversion pushes you over an IRMAA threshold two years later, will usually move more money than the state line does. The state answer tells you whether to convert here; the federal answer tells you how much to convert at once.
Paying the tax from outside the account matters more than either. Using converted dollars to pay the bill shrinks the balance that was the entire point of converting.
Sources
Authority: NH DRA Technical Information Release 2025-001 (I&D repeal); former RSA 77 (repealed).
Compiled from state statutes, session laws and revenue-department publications and adversarially verified in July 2026. Dataset confidence for New Hampshire: high.
This page states what the cited authority says. It is not tax advice, and a conversion large enough to matter is worth putting in front of a preparer who can see your whole return.