Connecticut Stock Options Tax: 6.99% Top Rate, a CT State AMT on ISO Exercises, and QSBS Conformity

Connecticut's stock option tax picture has three distinct layers that most tech employees overlook. First, Connecticut's 6.99% top rate applies to all capital gains as ordinary income — a qualifying ISO disposition that generates long-term capital gain at 15%–20% federally still faces up to 6.99% in Connecticut with no preferential rate.¹ Second, Connecticut maintains a state alternative minimum tax calculated directly off the federal AMT — meaning ISO exercises that generate a federal AMT bill also generate a separate Connecticut state AMT charge layered on top.² Third, and favorably: Connecticut conforms to the federal §1202 QSBS exclusion, so startup founders and early employees who qualify can exclude QSBS gains from both federal and Connecticut income tax — unlike California, Oregon, and Pennsylvania, which have all decoupled from §1202.³

There is also a less-discussed provision that affects high earners specifically: Connecticut's "tax recapture" mechanism phases out the benefit of lower brackets for single filers with Connecticut AGI above approximately $105,000 and MFJ filers above approximately $210,000.⁴ In practice, this means high-income tech employees exercising large option tranches can face effective marginal rates that approach the 6.99% top rate across a much wider income range than the bracket schedule suggests. For a Gartner engineer in Stamford or a Booking Holdings employee in Norwalk exercising $500,000 of NQSOs, Connecticut's effective marginal rate on the exercise spread is generally 6.99% — the nominal top rate, applied throughout because the recapture mechanism eliminates lower-bracket savings.

The summary: Connecticut is less costly than New York (no NYC add-on, lower top rate) and less costly than New Jersey for the highest earners — but Connecticut's unique state AMT adds a cost that New York and New Jersey ISO holders don't face. The QSBS conformity is a genuine advantage over California, Oregon, and Pennsylvania. For Connecticut residents in the Greenwich/Stamford corridor who work in New York City, the CT–NY tax interaction needs careful modeling, as CT gives a credit for NY taxes paid on NY-source income.

Connecticut Income Tax Rates 2026

Connecticut's individual income tax has seven progressive brackets for 2026, ranging from 2% to 6.99%.¹ For single filers:

• 2% on Connecticut taxable income up to $10,000
• 4.5% on income $10,001–$50,000
• 5.5% on income $50,001–$100,000
• 6% on income $100,001–$200,000
• 6.5% on income $200,001–$250,000
• 6.9% on income $250,001–$500,000
• 6.99% on income above $500,000

For married filing jointly:

• 2% on income up to $20,000
• 4.5% on income $20,001–$100,000
• 5.5% on income $100,001–$200,000
• 6% on income $200,001–$400,000
• 6.5% on income $400,001–$500,000
• 6.9% on income $500,001–$1,000,000
• 6.99% on income above $1,000,000

The bottom two rates (2% and 4.5%) were reduced from 3% and 5% by the Connecticut legislature in 2024. For most senior tech employees with large option exercises, the practical marginal rate is 6.99% on the entire exercise spread because the recapture provision eliminates the lower-bracket benefit for higher-income taxpayers (see below).

The Connecticut Tax Recapture Provision

Connecticut includes a "tax recapture" mechanism that phases out the benefit of lower tax brackets for taxpayers above certain income thresholds.⁴ The recapture begins at approximately $105,000 Connecticut AGI for single filers ($210,000 for married filing jointly). As income rises above these thresholds, a supplemental add-back effectively restores tax on lower-bracket income at the higher rates — so that at high income levels, the entire income is effectively taxed at or near the top marginal rate.

For stock option planning purposes, this means a Stamford tech employee with $200K base salary exercising $400K of NQSOs should model their total Connecticut tax at roughly 6.9%–6.99% on the full exercise spread — not the blended bracket rate the schedule alone would suggest. The brackets are still technically in force (you won't literally pay 6.99% on every dollar), but the recapture narrows the benefit of lower brackets significantly for high earners.

Connecticut's State AMT on ISO Exercises

This is the most consequential planning distinction for Connecticut ISO holders. Most neighboring states in the Northeast — New York, New Jersey, Massachusetts — have no state alternative minimum tax at all. Connecticut does: CGS §12-701(a)(6) establishes a Connecticut AMT calculated as the lesser of:²

• 19% of the adjusted federal tentative minimum tax (from federal Form 6251), after Connecticut modifications, or
• 5.5% of adjusted federal alternative minimum taxable income (federal AMTI after Connecticut modifications)

Connecticut uses the smaller of the two calculations. Because ISO exercise spreads are an AMT preference item under IRC §56(b)(3), they increase federal AMTI — and thus trigger the Connecticut state AMT formula even though no Connecticut regular income tax is due at exercise. The Connecticut AMT is computed on Form CT-6251.

Connecticut's state AMT is distinct in structure from other states that impose one. California (7% state AMT) and Minnesota (6.75% state AMT) calculate their state AMTs as standalone rates applied to their own state AMT base. Connecticut's method — 19% of the federal tentative minimum tax or 5.5% of federal AMTI, whichever is less — produces an effective rate on the ISO spread that is generally in the range of 4%–5.5%, depending on the taxpayer's total income and how the phaseout of the federal AMT exemption affects the federal tentative minimum tax. This is lower than California's 7% and Minnesota's 6.75%, but still a meaningful cost that New York, New Jersey, Massachusetts, and Illinois ISO holders do not face at all.

NQSO Treatment in Connecticut

Nonqualified stock option exercises generate ordinary W-2 income (the spread between exercise price and FMV at exercise), subject to Connecticut income tax at rates up to 6.99%.¹ Any capital gain on shares held after exercise is taxed as ordinary income in Connecticut — Connecticut provides no preferential rate for long-term capital gains. This applies equally to short-term and long-term gains from NQSO-originated shares.

ISO Qualifying and Disqualifying Dispositions in Connecticut

Qualifying dispositions

A qualifying ISO disposition — shares held at least 2 years from grant date and at least 1 year from exercise date under IRC §422(a)(1) — generates long-term capital gain federally (0%, 15%, or 20% depending on total income) plus 3.8% federal NIIT above applicable thresholds. In Connecticut, that same qualifying disposition is taxed at ordinary income rates up to 6.99% — no preferential rate for the long-term hold.¹

The implication: for Connecticut ISO holders, the qualifying-disposition premium (holding long enough to achieve federal LTCG rates) provides a large federal benefit (potentially 37% ordinary income reduced to 20% LTCG) but provides no Connecticut benefit. The Connecticut rate on the eventual qualifying sale is the same as it would be on a disqualifying disposition. This shifts the qualifying-vs-disqualifying analysis for Connecticut residents: the Connecticut state AMT paid at exercise is the additional cost of holding for qualifying-disposition treatment, and the recovery of that state AMT (via the CT AMT credit) depends on a future disqualifying sale. For large ISO grants, modeling both paths with a Connecticut-aware tax advisor is essential.

Disqualifying dispositions

A disqualifying ISO disposition (selling before satisfying the 2-year/1-year holding requirements) converts the exercise-date spread to W-2 ordinary income, taxed in Connecticut at rates up to 6.99%. Any gain above exercise-date FMV becomes short-term capital gain — also taxed as ordinary income in Connecticut. There is no FICA on the disqualifying disposition spread per IRC §3121(a)(22)(B).

Importantly, a disqualifying disposition eliminates the Connecticut state AMT problem entirely: when you sell in a disqualifying disposition, the ISO spread is reclassified as regular W-2 income. If you paid Connecticut state AMT on the exercise-year spread and then sell in a disqualifying disposition, you should be entitled to a Connecticut AMT credit (Form CT-8801) to recover previously paid Connecticut state AMT against future Connecticut regular income tax liability. Consult a Connecticut-licensed CPA to confirm the AMT credit recovery path for your specific situation.

QSBS in Connecticut: Full Federal Conformity

Connecticut conforms to the federal §1202 QSBS exclusion.³ Because Connecticut individual income tax begins with federal adjusted gross income (CGS §12-701), gains excluded from federal AGI under §1202 are also excluded from Connecticut taxable income. Connecticut applies no additional state-level tax on federally excluded QSBS gains.

For 2026, this conformity includes the OBBBA-era §1202 rules: tiered exclusions of 50%/75%/100% at 3/4/5 years of holding, with a $15M gain cap (or 10× adjusted basis) and a $75M gross asset limit for qualifying issuances after July 4, 2025. Gains excluded federally are excluded in Connecticut at the same amount. Connecticut state tax on federally excluded QSBS gain: $0.

No City Income Tax in Connecticut

Connecticut municipalities do not impose a city income tax on wages or investment income.¹ There is no Stamford city income tax, no Greenwich city income tax, no Hartford city income tax, and no Norwalk city income tax. Stock option income — NQSO exercises, disqualifying ISO dispositions, qualifying ISO dispositions, RSU vesting — is taxed at the state level only.

This is a meaningful planning distinction versus New York City. A tech employee exercising $500K of NQSOs as a Connecticut resident working in Connecticut owes approximately $34,950 in state income tax. The same employee as a New York City resident working in Manhattan would owe approximately $67,630 (NY state ~$48,250 + NYC ~$19,380 combined). Connecticut's absence of a city income tax is a genuine cost advantage over the NYC tax package — but requires that the employee actually works primarily in Connecticut (not just claims Connecticut residence while commuting daily to a New York City office).

Connecticut–New York Commuter Sourcing: The Critical Interaction

Fairfield County is one of the densest commuter corridors in the country — a large share of Stamford, Greenwich, and Westport-area residents work in New York City. This creates a critical sourcing interaction for stock option income.

When a Connecticut resident performs work in New York, New York sources that income to New York based on the workday fraction (days in New York / total workdays during the allocation period). New York nonresident income tax applies to the NY-sourced portion. Connecticut, in turn, gives a credit under CGS §12-704 for income taxes paid to another state on income that is also subject to Connecticut tax — so the effective rate for income doubly taxed is the higher of the two states' rates (not the sum), provided the CT credit fully offsets the lower rate.⁶

The practical result for most CT–NY commuters with large NQSO/RSU awards: New York's higher rate (9.65%–10.9% for $1M+ earners) exceeds Connecticut's 6.99% top rate on NY-sourced income. The Connecticut credit offsets the Connecticut tax entirely, and the employee effectively pays New York's rate on the NY-sourced portion. On income sourced to Connecticut (work performed in CT), the employee pays only Connecticut tax at 6.99%. The overall rate is a weighted average of the two states depending on the sourcing ratio.

New York's convenience-of-employer rule adds a further complication: if a Connecticut resident works for a New York employer and their employer has a New York office, days worked remotely in Connecticut may be sourced to New York under the COE rule — unless the employee can demonstrate that their home office is a "bona fide employer office" for New York purposes. This can push the NY-sourced fraction above the actual days physically in New York.

Connecticut's Nonresident Sourcing Method: Compensation Ratio, Not Workday Fraction

For former Connecticut residents who moved away but still hold unexercised options from a CT-era employer, Connecticut uses a distinctive sourcing method for nonresidents: the compensation ratio.⁵ Rather than counting workdays in Connecticut versus total workdays during the grant-to-exercise period (as California and New York do), Connecticut uses the ratio of total compensation received from the grantor while the employee was working in Connecticut versus total compensation received from the same grantor during the allocation period.

The Connecticut Supreme Court's decision in Allen v. Commissioner of Revenue Services (December 2016) confirmed this approach: the court upheld Connecticut's right to tax NQSO income of an individual who had earned compensation solely in Connecticut — even though the options were exercised after the taxpayer had moved to another state. Connecticut's compensation-ratio sourcing is based on what you were paid while working in Connecticut, not how many days you logged there.

Six Planning Strategies for Connecticut Stock Option Holders

1. Model the Connecticut state AMT separately from the federal AMT before exercising ISOs

Most ISO exercise planning tools model only the federal AMT. In Connecticut, that is not sufficient. Use the ISO AMT Calculator to establish your federal AMT exposure, then separately calculate the Connecticut state AMT using the lesser-of formula: 19% × (federal tentative minimum tax) or 5.5% × (federal AMTI). For large ISO exercises where the federal tentative minimum tax is substantial, the Connecticut state AMT will typically fall in the range of $15,000–$40,000 or more on exercises of $500K–$1M of spread. Work with a Connecticut-licensed CPA to verify the exact CT-6251 calculation for your situation before exercising, since the specific Connecticut modifications to federal AMTI affect the result.

2. Run the qualifying-vs-disqualifying analysis with Connecticut state AMT in mind

For New York or New Jersey ISO holders, the qualifying vs. disqualifying disposition is primarily a federal question (15%–20% LTCG vs. 37% ordinary income). For Connecticut ISO holders, there is an additional factor: the state AMT paid at exercise. If you hold for a qualifying disposition, Connecticut taxes the eventual gain at up to 6.99% (same as ordinary income) with no LTCG preference — meaning the qualifying hold gives you a large federal tax benefit but zero Connecticut benefit. The Connecticut state AMT paid at exercise is a real, upfront cost that is not recovered on a qualifying sale. In contrast, a disqualifying sale recovers the Connecticut state AMT via the CT-8801 credit. For large ISO tranches where the Connecticut state AMT is substantial, the disqualifying-disposition path may result in a lower combined federal + Connecticut total tax than the qualifying hold, depending on your federal bracket and the absolute size of the exercise spread. Model both paths.

3. Use QSBS conformity for early-exercise planning at qualifying Connecticut startups

Connecticut startups in Hartford, New Haven, Stamford, and the Fairfield County innovation corridor can offer their founders and early employees the full §1202 QSBS benefit — excluded from both federal and Connecticut income. If you have early-exercise rights on ISO or NQSO grants at a qualifying C-corp (≤$75M gross assets at issuance, eligible business type, domestic C-corp), exercising immediately at grant and filing an 83(b) election within 30 days starts the federal and Connecticut QSBS clocks simultaneously. After 5+ years on post-July 4, 2025 stock, up to $15M of gain is excluded from both federal and Connecticut income tax. On a $10M qualifying gain, that is approximately $699,000 in Connecticut state tax avoided.

4. Understand your CT–NY sourcing ratio if you commute to New York City

If you are a Connecticut resident who commutes to a New York City office (or works for a New York employer under the COE rule), your NQSO and RSU income is partially sourced to New York. You owe New York nonresident tax on the New York-sourced fraction and get a Connecticut credit for that New York tax. The effective combined rate depends on the sourcing ratio. Work out your actual workday split: days physically in New York vs. total workdays during the grant-to-exercise period. If New York's rate exceeds Connecticut's on the NY-sourced income (which it usually does for earnings above $500K), the Connecticut credit will fully offset the CT tax on that portion, and you will effectively pay New York's higher rate on NY-sourced income and Connecticut's 6.99% on CT-sourced income. Modeling this correctly often reveals that concentrated exercise in a single year can push total effective state rates well above the nominal Connecticut 6.99%.

5. If you recently relocated from Connecticut, calculate the CT compensation ratio before exercising

Former Connecticut residents holding unexercised grants from a Connecticut employer face nonresident Connecticut tax under the compensation-ratio method at up to 6.99%. Unlike workday-fraction states where each additional day outside the state reduces the numerator, Connecticut's ratio is driven by compensation received — the CT numerator is fixed once you leave, while the denominator grows with each paycheck from the same employer. The longer you wait after relocating before exercising, the lower your Connecticut sourcing ratio and the smaller your Connecticut nonresident bill. For large grants with several years remaining before they expire, the incremental Connecticut tax saving from delayed exercise can be significant. Calculate the ratio at the current date and at 6–12 months out, and compare the Connecticut tax savings against any stock price risk or other exercise-timing constraints before making a decision.

6. Coordinate CT state AMT credit recovery for past ISO exercises

If you exercised ISOs while a Connecticut resident and paid Connecticut state AMT in a prior year (reported on your CT-6251), you may have a Connecticut AMT credit carryforward (Form CT-8801) that can offset future Connecticut regular income tax. This credit recovers over time as you have regular Connecticut income tax liability exceeding what the AMT would otherwise require. Unlike the federal AMT credit, which can be accelerated by making disqualifying dispositions that convert ISO AMT preference items to regular income, the Connecticut AMT credit recovery depends on future regular CT tax liability. Review your prior CT-6251 and CT-8801 filings with a Connecticut CPA to verify whether you have an outstanding credit and how quickly it can be recovered against future Connecticut income — particularly if you are in a lower-income year or planning a large disqualifying disposition.

1. Connecticut income tax brackets and no LTCG preference, 2026. Connecticut's individual income tax has seven brackets ranging from 2% to 6.99%, with the top 6.99% rate applying to income above $500,000 for single filers and $1,000,000 for married filing jointly. The bottom two rates were reduced from 3% and 5% to 2% and 4.5% by the Connecticut General Assembly in 2024. Connecticut treats all capital gains — short-term and long-term alike — as ordinary income subject to the same bracket schedule; no preferential rate exists for long-term capital gains. Sources: Connecticut Department of Revenue Services — Individual Income Tax (portal.ct.gov); Tax Foundation — 2026 State Income Tax Rates and Brackets; Connecticut General Assembly OLR — 2026 Tax Report.
2. Connecticut state AMT under CGS §12-701(a)(6), Form CT-6251. Connecticut imposes a state alternative minimum tax equal to the lesser of (a) 19% of the adjusted federal tentative minimum tax (from Form 6251, after Connecticut modifications) or (b) 5.5% of adjusted federal alternative minimum taxable income. The CT AMT is compared to regular Connecticut income tax; the taxpayer pays whichever is higher. ISO exercise spreads are an AMT preference item under IRC §56(b)(3), which Connecticut incorporates by reference — meaning ISO exercises that generate federal AMT liability also generate Connecticut state AMT liability computed under the CT-6251 formula. Connecticut AMT credits paid in excess of regular income tax are recoverable in future years via Form CT-8801. Sources: CCH AnswerConnect — Connecticut Alternative Minimum Tax Adjustments; Connecticut General Assembly OLR — Connecticut Alternative Minimum Tax (2015-R-0289).
3. Connecticut §1202 QSBS conformity. Connecticut begins its individual income tax calculation with federal adjusted gross income (CGS §12-701 et seq.). Because gains excluded from federal AGI under IRC §1202 (qualified small business stock) are not included in federal AGI, they are also not included in Connecticut taxable income — Connecticut conforms to §1202 by this starting-point mechanism. This includes the OBBBA-era §1202 rules (effective July 4, 2025): tiered 50/75/100% exclusion at 3/4/5 years, $15M gain cap, $75M gross asset limit at issuance. Sources: Keystone Global Partners — 2026 QSBS by State: Eligibility Index; The Startup Law Blog — 2026 QSBS State-by-State Conformity Guide.
4. Connecticut tax recapture provision. Connecticut phases out the benefit of lower income tax brackets for taxpayers above certain income thresholds. The recapture mechanism begins at approximately $105,000 Connecticut AGI for single filers ($210,000 for married filing jointly). The supplemental add-back eliminates the tax savings from lower-bracket income, effectively pushing marginal rates toward the top rate of 6.99% for higher-income taxpayers. This means the effective marginal rate for high-income Connecticut residents making large NQSO exercises or capital gains transactions is generally 6.99% across the exercise spread. Sources: Connecticut General Assembly OLR — 2026 Tax Report; Tax Foundation — Connecticut 2026 State Tax Competitiveness Index.
5. Connecticut nonresident sourcing using compensation ratio method; Allen v. Commissioner of Revenue Services. Connecticut sources nonresident stock option income using the ratio of in-state compensation received from the option grantor to total compensation received from the same grantor during the allocation period — not a workday-count fraction as used by California, New York, and most other states. This approach was affirmed in Allen v. Commissioner of Revenue Services (Connecticut Supreme Court, December 2016), which held that Connecticut could tax a taxpayer's full NQSO income even though the options were exercised after the taxpayer had relocated to another state, because all of the relevant compensation was earned while the taxpayer worked in Connecticut. Former Connecticut residents with options from a Connecticut-period employer remain subject to Connecticut nonresident tax under this compensation-ratio methodology. Sources: EisnerAmper — Connecticut Tax on Nonresident Stock Options (blog post); Financial Planning Association — State Income Taxation of Nonresident Equity-Based Compensation (Oct 2022).
6. Connecticut credit for income taxes paid to other states (CGS §12-704). Connecticut allows resident taxpayers a credit against Connecticut income tax for income taxes paid to another state on income that is also subject to Connecticut tax. For Connecticut residents with income sourced to New York (including NQSO and RSU income allocated to New York workdays), the CT credit offsets Connecticut tax on that income — meaning the effective rate for CT residents is the higher of the two states' rates, not both rates stacked. Sources: Connecticut DRS — Resident Income Tax Information; Phoenix Strategy Group — State Tax Rules for Nonresident Equity Compensation.

Values verified June 2026. Connecticut 2026 income tax brackets from Connecticut DRS publications and Connecticut General Assembly OLR reports. CT state AMT under CGS §12-701(a)(6) and Form CT-6251 instructions. QSBS conformity based on Connecticut AGI starting-point mechanism as confirmed by current-year practitioner sources. Allen v. Commissioner of Revenue Services (December 2016) for compensation-ratio sourcing. The Connecticut state AMT interaction with specific ISO exercise scenarios requires verification with a Connecticut-licensed tax advisor. Confirm current-year values before making irreversible decisions.