Roth Conversion Cost by State 2026: $0 to $13,300 Index

In 2026, a standardized $100,000 Roth conversion generates $0 in state income tax in nine US states and as much as $13,300 in California at its top marginal rate, a spread of $13,300 that no federal rule touches and that a top-marginal-rate ranking states differently from what a typical retiree actually pays (Source: Tax Foundation, 2026; author calculation).

Q3 Advisors Research | Last updated July 2026 | Methodology and sources below

This briefing introduces the Roth Conversion State Cost Index (RCSCI): the 2026 state income tax cost per $100,000 of Roth conversion income, ranked across all 51 US jurisdictions. A Roth conversion is taxed as ordinary income in the year it occurs under IRC section 408A, so the state cost is set by each state’s ordinary-income rate structure, its retirement-income rules, and the taxpayer’s residency on the conversion date. The index is paired with the federal stack that sits on top of every state figure, and a relocation-arbitrage calculation grounded in federal law. For planning context, see our overview of Roth conversion strategy.

Executive summary

Key findings

• A $100,000 Roth conversion costs $0 in state income tax in 9 of 50 states in 2026, all of which levy no broad individual income tax (Source: Tax Foundation, 2026).
• California’s 2026 top marginal rate of 13.3% equals $13,300 of state tax per $100,000 converted, the highest of any US jurisdiction (Source: Tax Foundation, 2026).
• A married California household with about $80,000 of other taxable income pays roughly $8,050 in state tax on a $100,000 conversion in 2026, an 8.05% effective rate, because the 13.3% rate does not apply below $1,354,550 of income (Source: California FTB, 2026; author calculation).
• The median 2026 top marginal rate across 51 jurisdictions is 4.7%, so California’s top rate takes about 2.8 times the median-state cost per $100,000 converted (Source: Tax Foundation, 2026; author calculation).
• Illinois applies a 4.95% flat rate in 2026 and subtracts federally taxable distributions from qualified retirement plans; on the author’s reading of 35 ILCS 5/203 this reaches a Roth conversion, so a qualifying Illinois retiree may pay $0 state tax on the conversion, subject to confirmation of the conversion-income treatment per taxpayer (Source: 35 ILCS 5/203; author reading).
• Pennsylvania applies a 3.07% flat rate in 2026 but does not tax a traditional-to-Roth conversion completed by trustee-to-trustee transfer or 60-day rollover under its personal income tax (Source: PA Dept of Revenue, 2026).
• Washington levies a 7% tax on certain capital gains in 2026 but does not tax ordinary income, so a Roth conversion incurs $0 Washington tax (Source: Tax Foundation, 2026).
• The 2026 US federal Net Investment Income Tax of 3.8% applies once MAGI exceeds $200,000 for single filers or $250,000 for joint filers, thresholds set by statute and not indexed since 2013 (Source: IRC section 1411; CRS IF11820).
• The first 2026 Medicare IRMAA tier begins above $109,000 of individual MAGI or $218,000 of joint MAGI (US federal), based on 2024 income under the two-year lookback (Source: CMS/SSA, 2025).
• Crossing the first 2026 IRMAA tier adds $81.20 per month to Medicare Part B, equal to $974.40 per enrollee for the year, or about $1,948.80 for a two-enrollee couple (Source: 2026 CMS IRMAA schedule via cross-checked secondary reproduction; author calculation).
• The 2026 US federal marginal cost of a conversion ranges from $1,000 per $10,000 at the 10% bracket to $3,700 per $10,000 at the 37% bracket, which begins above $640,600 for single filers and $768,700 for joint filers (Source: IRS Rev. Proc. 2025-32, 2025).
• For US taxpayers aged 65 and older, the OBBBA senior deduction phaseout raises a conversion’s effective federal rate to about 1.06 times the statutory rate within the $75,000 to $175,000 MAGI band for singles (Source: OBBBA P.L. 119-21, 2025).
• An illustrative $300,000 conversion for a joint household with $80,000 of other taxable income costs about $93,900 total tax in California versus about $67,300 in Texas in 2026, a $26,600 difference that is entirely California state tax (Source: IRS, 2025; California FTB, 2026; author calculation).

The metric: what the RCSCI measures

The Roth Conversion State Cost Index states the 2026 state income tax on a standardized $100,000 conversion, expressed both as the top-marginal-rate ceiling and, for the states where it can be computed exactly, as the amount a mass-affluent retiree actually pays. A conversion is ordinary income, not a capital gain and not a tax-favored retirement distribution in most states, so it is generally taxed at the state’s ordinary rate schedule in the year of conversion. The index isolates the state layer so it can be added to the separately reported federal layer.

The nine no-income-tax states impose $0 on a conversion in 2026 (Source: Tax Foundation, 2026). Fifteen states apply a single flat rate in 2026, so the conversion cost equals that rate times the converted amount with no bracket ambiguity, and Massachusetts applies a flat 5% with a 4% surtax above $1,000,000 (Source: Tax Foundation, 2026). Twenty-five states and the District of Columbia use graduated brackets in 2026, where the cost depends on where the conversion stacks in the income range (Source: Tax Foundation, 2026). Three flat-rate states, Pennsylvania, Illinois, and Mississippi, may remove conversion income from the state base for qualifying retirees, a treatment a top-rate ranking does not capture; Pennsylvania’s is the clearest and the Illinois and Mississippi conversion-income results are the author’s reading of the cited statutes (Source: PA Dept of Revenue; 35 ILCS 5/203; Miss. Code section 27-7-15).

The number that people actually pay is often lower than the headline top rate, because top rates in high-tax states begin at very high incomes. California’s 13.3% rate begins above $1,354,550 of joint taxable income in 2026, and New York’s 10.9% rate begins above $25,000,000 in 2026 (Source: California FTB, 2026; Tax Foundation, 2026). A retiree converting into a $100,000-to-$180,000 income band lands in the middle of these schedules, not at the top. Readers weighing how large a conversion to run can review our note on how much to convert to Roth.

The ranked dataset: state tax per $100,000 converted, 2026

The table below ranks all 51 US jurisdictions by the 2026 top-marginal-rate cost per $100,000 converted, with the exact treatment of conversion income noted for each. For flat-rate and no-income-tax states, the listed cost is what a retiree pays. For graduated states, the listed cost is the ceiling that applies only at the top bracket, and the treatment column flags where a retiree pays less. This is the citable asset.

The single most citable line: 9 of 50 states charge $0 state tax on a Roth conversion in 2026, the median state charges $4,700 per $100,000, and California’s ceiling of $13,300 is the highest, a top-to-bottom spread of $13,300 (Source: Tax Foundation, 2026; author calculation). For a deeper treatment of state rules, see our page on Roth conversion state taxes.

Headline rate versus what retirees actually pay

A top-marginal-rate ranking quotes each state’s top rate, which overstates the cost for retirees who never reach the top bracket. The table below restates the three highest-population high-tax states to the rate that applies in a realistic conversion band, defined as a married household with about $80,000 of other taxable income converting $100,000, so the conversion occupies roughly the $80,000 to $180,000 income range. The gap between the headline top rate and the realistic mid-band rate is the distinction this index isolates.

A married California household with about $80,000 of other taxable income pays roughly $8,050 in California tax on a $100,000 conversion in 2026, not the $13,300 a top-rate ranking implies (Source: California FTB, 2026; author calculation). The overstatement in a top-rate ranking of California reaches $5,250 per $100,000 for that household (author calculation). Flat-rate and no-tax states carry no such gap, because their headline figure is what everyone pays (Source: Tax Foundation, 2026).

The retirement-exclusion states behind the headline rates

Some income-tax states remove qualified retirement income from the state base, so a resident with an income tax may pay little or nothing on a conversion. This is the counterintuitive result: a flat-tax state can cost less on a conversion than its rate suggests. Whether these exclusions reach conversion income, and not only later withdrawals, varies by state, and eligibility conditions differ and should be confirmed for each taxpayer before relying on a $0 result.

Pennsylvania applies a 3.07% flat rate in 2026 but treats a traditional-to-Roth conversion completed by trustee-to-trustee transfer or within a 60-day rollover as not taxable under its personal income tax, so the state cost is $0; this rollover treatment is the clearest of the three (Source: PA Dept of Revenue, 2026). Illinois applies a 4.95% flat rate in 2026 and subtracts federally taxable distributions from qualified retirement plans under 35 ILCS 5/203; on the author’s reading this subtraction reaches a Roth conversion, which would make the state cost $0 for a qualifying retiree, though the conversion-income treatment is not settled by a pinpoint ruling and should be confirmed (Source: 35 ILCS 5/203; author reading). Mississippi applies a 4.0% flat rate in 2026 and exempts qualified retirement income for recipients who have separated from service and reached qualifying age; the author reads this to cover a qualifying retiree’s conversion for a $0 state cost, again subject to per-taxpayer confirmation (Source: Miss. Code section 27-7-15; author reading). Counting these three with the nine no-income-tax states, up to 12 states may impose $0 state tax on a qualifying retiree’s 2026 conversion (author synthesis).

The federal stack that sits on every state figure

State tax is only one layer. Every conversion also carries a federal ordinary-income cost, a possible 3.8% surtax, and possible Medicare surcharges, all driven by the same conversion dollars. These federal costs are identical whether the taxpayer lives in Texas or California, so they set the floor beneath the state ranking.

These are US federal costs, identical in every state. The 2026 US federal ordinary brackets run from 10% to 37%, with the 37% bracket beginning above $640,600 for single filers and $768,700 for joint filers (Source: IRS Rev. Proc. 2025-32, 2025). The federal marginal cost is $1,000 per $10,000 converted at 10%, $2,200 at 22%, $2,400 at 24%, and $3,700 at 37% (Source: IRS Rev. Proc. 2025-32, 2025; author calculation). The 2026 Net Investment Income Tax of 3.8% is not levied on the conversion itself, because retirement distributions are excluded from net investment income, but the conversion raises MAGI and can pull other investment income over the threshold, adding up to $380 per $10,000 of investment income exposed (Source: IRC section 1411; CRS IF11820). The 2026 US federal NIIT thresholds are $200,000 of MAGI for single filers, $250,000 for joint filers, and $125,000 for married filing separately, set by IRC section 1411 and not indexed since 2013 (Source: IRC section 1411). Our guide to the Roth conversion break-even shows how these layers change the payback period.

Medicare IRMAA is a cliff, not a phase-in. The standard 2026 Medicare Part B premium is $202.90 per month (US federal), and IRMAA adds a surcharge once 2024 MAGI crosses a tier set by CMS and SSA (Source: CMS/SSA, 2025). The first 2026 tier begins above $109,000 of individual MAGI or $218,000 of joint MAGI and adds $81.20 per month, equal to $974.40 per enrollee for the year (Source: 2026 CMS IRMAA schedule via cross-checked secondary reproduction; author calculation). Crossing a tier by a single dollar imposes the full surcharge for 12 months, and for a two-enrollee couple the first-tier cost is about $1,948.80 for the year (author calculation). Our 2026 Medicare IRMAA bracket guide details every tier.

Relocation arbitrage and the residency-timing rule

Because state tax is set by residency on the conversion date, a pre-conversion move can eliminate the state layer entirely. Federal law at 4 USC section 114, enacted as P.L. 104-95 in 1996, prohibits a state from taxing the retirement income of a person who is not a resident of that state, which means a former high-tax state cannot reach back for a conversion completed after the taxpayer has changed domicile (Source: 4 USC section 114, 1996). The rule turns on being a nonresident of the old state and a resident of the new state on the date the conversion is reported.

Most states determine residency by domicile plus a physical-presence test, and many treat 183 days in-state as a statutory-residence threshold, so a taxpayer generally must abandon the old domicile and be present in the new state past that line to escape the old state’s tax on the conversion (author synthesis of state residency statutes). A New York resident who converts $100,000 while still a New York resident owes New York tax on 100% of the conversion at the applicable New York rate, roughly $5,900 in the mid-band or up to $10,900 at the top rate in 2026 (Source: Tax Foundation, 2026; author calculation). The same taxpayer who first establishes residency outside New York and converts as a nonresident would owe New York $0 on the conversion, because 4 USC section 114 bars New York from taxing a nonresident’s retirement distribution; that $0 outcome depends on a domicile change that is validly completed before the conversion date and that holds up on audit (Source: 4 USC section 114, 1996). High-tax states audit residency changes aggressively, so a partial or contested move can leave the old state’s tax in place, and documentation of the move date relative to the conversion date carries real weight (author note).

The dollars at stake scale with the conversion. For a married household with about $80,000 of other taxable income, a $500,000 conversion in 2026 incurs roughly $45,250 of California tax in the 9.3% band, so completing the conversion after a move to a no-income-tax state avoids about $45,000 to $47,000 of state tax (Source: California FTB, 2026; author calculation). From a median-rate state at 4.7%, the same $500,000 conversion state cost is about $23,500 (author calculation).

Original synthesis

Insight 1: The RCSCI top-to-bottom spread and median

Formula: for each of the 51 jurisdictions, state tax per $100,000 = 2026 top marginal rate times $100,000; the index is the ranked set, the spread is the maximum minus the minimum, and the median is the 26th ranked value. Inputs: Tax Foundation 2026 top marginal rates for all 51 jurisdictions (each cited above). Result: the maximum is California at $13,300, the minimum is $0 in nine states, the spread is $13,300, and the median is Missouri at $4,700 (author calculation). Limitation: the top-rate basis overstates cost for retirees in graduated states who do not reach the top bracket, which is why the realistic-marginal correction is reported separately.

Insight 2: The effective-cost correction for graduated states

Formula: for a married household with $80,000 of other taxable income, effective state cost on $100,000 = sum across each 2026 bracket segment between $80,000 and $180,000 of segment width times segment rate. Inputs: California FTB 2026 bracket schedule; the $80,000 base assumption; the $100,000 conversion size (each cited above). Result: California’s effective cost is about $8,050, or 8.05%, versus the $13,300 top-rate figure, a $5,250 overstatement in headline rankings (author calculation). Limitation: the result is specific to the stated income assumptions and filing status, and shifts with other income, deductions, and conversion size.

Insight 3: The 12-state zero-cost cohort

Logic: combine the nine states with no broad individual income tax with the three flat-rate states whose retirement rules may remove conversion income from the base. Inputs: Tax Foundation 2026 no-income-tax list; PA Department of Revenue guidance for Pennsylvania; 35 ILCS 5/203 for Illinois; Miss. Code section 27-7-15 for Mississippi (each cited above). Result: up to 12 states may impose $0 state tax on a qualifying retiree’s 2026 conversion, a cohort larger than the commonly cited nine (author synthesis). Limitation: the three exclusion states impose conditions such as age, separation from service, or rollover method, so the $0 result is contingent on the individual meeting those conditions; Pennsylvania’s rollover treatment is directly supported, while the Illinois and Mississippi conclusion that the exclusion reaches conversion income (rather than only later withdrawals) is the author’s reading of those statutes and is not settled by a pinpoint ruling here.

Figures

Source quality ranking

Tier 1, primary and official. IRS Rev. Proc. 2025-32 via IRS.gov for 2026 brackets, standard deduction, and capital-gains breakpoints; IRS Notice 2025-67 for 2026 retirement contribution limits; CMS/SSA for the 2026 standard Part B premium of $202.90 and the IRMAA MAGI thresholds; IRC section 1411 and CRS IF11820 for the NIIT; 4 USC section 114 (P.L. 104-95) for the nonresident source-tax bar; OBBBA P.L. 119-21 for TCJA rate permanence, the senior deduction, and the estate exemption; state statutes 35 ILCS 5/203 and Miss. Code section 27-7-15 (with the conversion-income reading of the Illinois and Mississippi statutes noted as the author’s interpretation in Data limitations).

Tier 2, credible secondary citing primary. Tax Foundation 2026 State Individual Income Tax Rates and Brackets for the 51-jurisdiction rate set; California Franchise Tax Board 2026 bracket schedule; Pennsylvania Department of Revenue guidance on Roth conversions; the 2026 per-tier IRMAA surcharge dollar amounts ($81.20 up to $487.00 per month for Part B), taken from a cross-checked secondary reproduction of the CMS 2026 table because the CMS.gov fact-sheet page returned an access error, and reconciled against the $202.90 standard-premium anchor and the statutory cost-sharing percentages.

Tier 3, reputable practitioner context. General practitioner commentary was used only for orientation and not for any published figure.

Excluded. Aggregator and marketing calculator pages that did not trace to a named primary source were excluded. The direct CMS.gov page returned an access error, so the IRMAA tier dollars were taken from a secondary reproduction of the CMS table and cross-checked; this is disclosed in Data limitations. Part D IRMAA dollar amounts were not verified to a primary figure and are excluded.

Most quotable statistics

Data limitations

• The 51-jurisdiction ranking uses 2026 top marginal rates; for graduated states this is a ceiling, and most retirees pay a lower mid-band rate (Source: Tax Foundation, 2026).
• Only each jurisdiction’s 2026 top marginal rate was verified per cell to Tax Foundation 2026 and, for the flagged states, to the state schedule. Specific top-bracket income thresholds for several graduated states (for example Wisconsin, Minnesota, New Mexico, Vermont, and Maine) were not individually verified to a 2026 state schedule, so those dollar thresholds have been omitted and only the verified top rate and its high-threshold character are shown (author note).
• Georgia’s 2026 flat rate is 4.99%, cut from 5.19% by HB 463, signed by the Governor on May 11, 2026 and effective January 1, 2026, and carried into the Georgia Department of Revenue 2026 withholding guidance; the rate remains on a phased-reduction schedule toward a 3.99% floor in later years, subject to revenue triggers, so a taxpayer should confirm the current-year rate before relying on it (Source: Georgia HB 463, 2026; Georgia Department of Revenue, 2026).
• Effective-cost figures for California, New York, and New Jersey assume a married household with about $80,000 of other taxable income and change with other income, deductions, filing status, and conversion size (author calculation).
• The Pennsylvania, Illinois, and Mississippi zero-cost results depend on conditions such as age, separation from service, or rollover method that must be confirmed per taxpayer; Pennsylvania’s rollover treatment is directly supported, while the Illinois (35 ILCS 5/203) and Mississippi (27-7-15) conclusion that the exclusion reaches conversion income, and not only later withdrawals, is the author’s reading of those statutes and is not established by a pinpoint ruling here (Source: state statutes, 2026; author reading).
• The CMS.gov IRMAA fact-sheet page returned an access error, so the per-tier surcharge dollars ($81.20 through $487.00 per month) were taken from a cross-checked secondary reproduction of the CMS 2026 table and reconciled against the $202.90 standard-premium anchor, not read from the CMS page directly; they are classified as Tier 2, not Tier 1 (Source: 2026 CMS IRMAA schedule via secondary reproduction).
• Part D IRMAA dollar amounts were not verified to a primary figure and are excluded from this briefing.
• Local income taxes, such as Maryland county tax and New York City tax, are not included in the state figures and would raise the total for affected residents (author note).
• The index covers ordinary-income treatment only and does not model AMT, Social Security taxability, ACA premium credit clawback, or capital-gains stacking triggered by a conversion.

Recommended dataset fields

A downloadable version of the RCSCI would contain, per jurisdiction: state name and postal code; 2026 top marginal rate; rate-structure type (none, flat, graduated); state tax per $100,000 at the top rate; realistic mid-band marginal rate for a stated income profile; conversion-treatment flag (fully taxed, retirement-exclusion, no income tax); statutory citation for any exclusion; local-tax indicator; and a residency-rule note field. A companion federal sheet would carry bracket, NIIT threshold, and IRMAA tier fields keyed to MAGI so a user can sum the state and federal layers for any conversion size.

Suggested headlines

• The 2026 Roth Conversion State Cost Index: $0 in 9 States, $13,300 in California
• Why California’s 13.3% Rate Overstates What Retirees Pay on a Roth Conversion by $5,250
• Twelve States That Can Charge $0 State Tax on a 2026 Roth Conversion
• Move First, Convert Second: The $45,000 Residency-Timing Rule for Roth Conversions
• The Full Stack: 50.3% on a 2026 California Conversion, Up to 54.1% Once NIIT Reaches Nearby Income

Frequently asked questions

How much state tax do you pay on a $100,000 Roth conversion in California versus Florida?

Florida charges $0 because it levies no individual income tax in 2026 (Source: Tax Foundation, 2026). California’s top rate of 13.3% equals $13,300, but that rate applies only above $1,354,550 of joint income, so a married household with about $80,000 of other taxable income pays roughly $8,050 in 2026 (Source: California FTB, 2026; author calculation). The California-versus-Florida gap for that household is about $8,050.

How many of the 50 states charge $0 state income tax on a Roth conversion?

Nine states charge $0 because they levy no broad individual income tax in 2026: Alaska, Florida, Nevada, New Hampshire, South Dakota, Tennessee, Texas, Washington, and Wyoming (Source: Tax Foundation, 2026). Washington’s 7% capital gains tax does not reach ordinary conversion income (Source: Tax Foundation, 2026). Counting Pennsylvania, Illinois, and Mississippi, which may exempt a qualifying retiree’s conversion, up to 12 states can charge $0, with the Illinois and Mississippi conversion-income treatment resting on the author’s reading of those statutes (author synthesis).

What percent of the conversion does the highest-tax state take, and how does that compare to the median state?

California’s top marginal rate of 13.3% is the highest, equal to $13,300 per $100,000 converted in 2026 (Source: Tax Foundation, 2026). The median 2026 top marginal rate across the 51 jurisdictions is 4.7%, equal to $4,700 per $100,000 (Source: Tax Foundation, 2026; author calculation). California’s top rate takes about 2.8 times the median-state figure.

How much can you save in state tax by moving to a no-income-tax state before converting $500,000?

For a married household with about $80,000 of other taxable income, a $500,000 conversion in 2026 incurs roughly $45,250 of California tax in the 9.3% band (Source: California FTB, 2026; author calculation). Completing the conversion as a resident of a no-income-tax state avoids about $45,000 to $47,000, subject to a valid residency change on the conversion date (Source: 4 USC section 114, 1996).

How many states with an income tax still tax little or none of a Roth conversion?

At least three income-tax states may leave a qualifying retiree’s 2026 conversion untaxed at the state level: Pennsylvania, whose personal income tax does not tax a conversion completed by rollover or trustee-to-trustee transfer; Illinois under 35 ILCS 5/203; and Mississippi under its qualified-retirement-income exemption (Source: state statutes, 2026). Pennsylvania’s rollover treatment is the clearest; the Illinois and Mississippi conclusion that the exclusion reaches conversion income is the author’s reading and should be confirmed per taxpayer before relying on a $0 result.

What is the combined federal, state, NIIT, and IRMAA marginal rate in the worst-case state in 2026?

In California at the top bracket, the 2026 marginal rate on the conversion dollars themselves is 50.3%: 37% US federal plus 13.3% California state (Source: IRS Rev. Proc. 2025-32, 2025; California FTB, 2026). The conversion is not itself net investment income, so it adds no NIIT on those dollars, but by raising MAGI it can pull other investment income into the 3.8% US federal NIIT, so the rates that can touch conversion-adjacent income sum to 54.1% (Source: IRC section 1411). Medicare IRMAA surcharges add a fixed dollar amount on top when a tier is crossed, up to $5,844 per enrollee for the year at the highest 2026 Part B tier (Source: 2026 CMS IRMAA schedule via cross-checked secondary reproduction; author calculation).

How much does a $100,000 conversion add to your Medicare Part B premium via IRMAA in 2026?

It depends on which 2026 tier your MAGI crosses. Crossing the first tier adds $81.20 per month, or $974.40 per enrollee for the year, and a two-enrollee couple pays about $1,948.80 (Source: 2026 CMS IRMAA schedule via cross-checked secondary reproduction; author calculation). At the highest 2026 tier the Part B add-on is $487.00 per month, or $5,844 per enrollee for the year (Source: 2026 CMS IRMAA schedule via cross-checked secondary reproduction; author calculation). Part D IRMAA stacks on top and is not quantified here.

What 2026 MAGI thresholds trigger the first IRMAA tier and the 3.8% NIIT?

The first 2026 IRMAA tier begins above $109,000 of individual MAGI or $218,000 of joint MAGI (US federal), based on 2024 income under the two-year lookback (Source: CMS/SSA, 2025). The 2026 US federal NIIT of 3.8% begins above $200,000 of single MAGI, $250,000 of joint MAGI, and $125,000 for married filing separately, thresholds set by IRC section 1411 and not indexed since 2013 (Source: IRC section 1411).

How long must you establish residency in a new state before a conversion escapes your old state’s tax?

Federal law at 4 USC section 114 bars a state from taxing a nonresident’s retirement income, so the test is your residency on the conversion date, not a fixed waiting period (Source: 4 USC section 114, 1996). Most states use domicile plus a physical-presence test, and many treat 183 days in-state as a statutory-residence line, so a taxpayer generally must abandon the old domicile and cross that presence threshold in the new state (author synthesis of state residency statutes).

What percent of a conversion does New York tax for a part-year resident who converts before versus after a move?

A person who converts while still a New York resident owes New York tax on 100% of the conversion, roughly 5.9% in the mid-band or up to 10.9% at the top rate in 2026 (Source: Tax Foundation, 2026; author calculation). A person who converts after establishing residency outside New York owes New York 0% of the conversion, because 4 USC section 114 bars New York from taxing a nonresident’s retirement distribution (Source: 4 USC section 114, 1996).

Sources

IRS, “IRS releases tax inflation adjustments for tax year 2026” (Rev. Proc. 2025-32), IRS.gov, October 2025, for 2026 ordinary brackets, standard deduction, section 63(f) additional deduction, long-term capital-gains breakpoints, and AMT exemption.
IRS, “401(k) limit increases to $24,500 for 2026” (Notice 2025-67), IRS.gov, 2025, for 2026 retirement contribution and section 415(c) limits.
CMS, “2026 Medicare Parts A and B Premiums and Deductibles,” CMS.gov, November 14, 2025, for the standard Part B premium of $202.90, the $283.00 deductible, and the IRMAA tier surcharges (tier dollars via a cross-checked secondary reproduction of the CMS table).
IRC section 1411 and Congressional Research Service report IF11820, Congress.gov, for the 3.8% Net Investment Income Tax, its thresholds, and the retirement-distribution exclusion.
4 USC section 114 (Pub. L. 104-95, 1996), for the prohibition on state taxation of nonresident retirement income.
One Big Beautiful Bill Act, Pub. L. 119-21, 2025, for TCJA rate permanence, the $6,000 senior deduction for 2025 through 2028, and the $15,000,000 federal estate and gift exemption.
Georgia HB 463, 2026, and the Georgia Department of Revenue 2026 Employer’s Withholding Tax Guide, for the reduction of the Georgia flat individual income tax rate to 4.99% effective January 1, 2026.
Tax Foundation, “2026 State Individual Income Tax Rates and Brackets,” taxfoundation.org, February 2026, for the top marginal rates and rate structures of all 50 states and the District of Columbia.
California Franchise Tax Board, 2026 tax rate schedules, for the California bracket thresholds used in the effective-cost calculations.
35 ILCS 5/203, for the Illinois subtraction of federally taxable retirement distributions.
Pennsylvania Department of Revenue, guidance on the taxability of Roth IRA conversions under the personal income tax.
Mississippi Code section 27-7-15, for the exemption of qualified retirement income.
IRS Publication 590-B and SECURE 2.0, for required minimum distribution ages 73 and 75.