In our 510,000-path Monte Carlo study of 30-year retirement outcomes, Connecticut retirees finished at 72.35% success rate (ranked #43 of 51 by success rate, #41 of 51 by lowest median lifetime state tax). Median 30-year state-tax cost: $88,074 — that is $88,074 more than a Wyoming retiree pays. Median terminal balance after 30 years: $824,333. State tax is part of the optimization here — the playbook below shows the federal-state-ACA stack.
The CT verdict
For a retiree planning withdrawals in 2026, Connecticut is one of the higher-burden states for retirees, especially on traditional pre-tax withdrawals. Agi thresholds for ss exemption ($75k single / $100k mfj), $13.61m estate exemption.
State tax meaningfully reduces the net benefit of a Roth conversion ladder. At this state's top marginal rate, every dollar converted costs both federal ordinary-income tax AND state tax — and crossing the 400% FPL ACA cliff layers on a third cost.
Worked example: $30k Roth conversion in Connecticut
Consider a married couple age 58 in Connecticut with $75,000 of taxable income, both on ACA Marketplace coverage. They want to convert $30,000 from a traditional IRA to a Roth. At Connecticut's 6.99% top marginal rate, the state tax on that conversion is approximately $2,097. Federal tax at the 22% bracket adds another $6,600. And because the conversion pushes their MAGI to $105,000 — over the 400% FPL cliff of $81,760 — they lose their full ACA premium tax credit, roughly $12,000. Total cost of the $30,000 conversion: about $20,697, or an effective 69.0% marginal rate. The federal-state-ACA stack matters in Connecticut.
Cost breakdown
| Component | Amount |
|---|---|
| Federal income tax (22% bracket) | $6,600 |
| Connecticut state income tax | $2,097 |
| ACA premium tax credit clawback | $12,000 |
| Total cost on $30,000 conversion | $20,697 (69.0% effective) |
Scenario B (high-tax): cliff-protective $15k conversion in Connecticut
A Connecticut couple aged 58 with $66K MAGI, both on a Silver-tier Marketplace plan converts only $15,000 because crossing the 400% FPL cliff in Connecticut layers state tax at 6.99%, federal tax at 22%, AND a ~$12,000 PTC clawback. State tax on $15k: $1,048. Federal tax: $3,300. PTC preserved. Effective rate: 29.0%. In a high-tax state, the optimization is small annual conversions over many years — never a single 'big year' if Marketplace coverage is in play.
What the Monte Carlo data says about Connecticut
QuantCalc Research ran a 30-year, 10,000-path Monte Carlo simulation for an identical representative retiree (age 60, $2M starting balance, 60/40 portfolio, $80K real annual spend) in each of the 51 U.S. jurisdictions. Here's how Connecticut compared to the best- and worst-case states:
| Metric | Connecticut | Wyoming (best) | California (worst) |
|---|---|---|---|
| 30-year success rate | 72.35% | 77.07% | 67.91% |
| Rank (of 51) | #43 | #1 | #51 |
| Median lifetime state tax (30y) | $88,074 | $0 | $167,580 |
| Median total tax (30y) | $306,474 | $218,400 | $385,980 |
| Median terminal balance | $824,333 | $996,189 | $652,555 |
| Δ success vs Wyoming | -4.72 pp | — | −9.16 pp |
Sources: QuantCalc 51-State Monte Carlo Study (2026-05-12) — 510,000 total paths, methodology fully documented and dataset released CC-BY-4.0. Connecticut's row in the dataset uses the same portfolio + spend + retirement age as every other state — the only variable is state tax treatment.
How Connecticut treats capital gains in retirement
Connecticut taxes long-term capital gains as ordinary income at the same top marginal rate (6.99%). That stacks on top of federal LTCG (0%/15%/20%) and the 3.8% NIIT for high earners. A 'free' federal 0% LTCG harvest still costs you 6.99% at the state level — meaningful in this jurisdiction, particularly during Roth-conversion years when your MAGI is already elevated.
Why the ACA cliff hits hard in Connecticut
The 400% federal-poverty-level cliff is federal, not state-specific — but its dollar impact depends on the benchmark Silver-plan premium in your county. Connecticut's Marketplace pricing and your household composition determine the size of the subsidy at risk. A two-person household near 400% FPL can easily have $10,000–$15,000 of annual premium tax credit on the line. Under the OBBBA 2026 restoration of the cliff, $1 of additional MAGI above 400% FPL eliminates the entire credit.
For 2026 the 400% FPL threshold is:
- Household of 1: $60,240
- Household of 2: $81,760
- Household of 3: $103,280
- Household of 4: $124,800
Optimal Roth conversion strategy for Connecticut
The CT-specific playbook depends on tier:
- Identify your cliff distance. Compute MAGI from all income sources (wages, capital gains, interest, dividends, traditional withdrawals). Find your headroom under 400% FPL. Use the live cliff widget above for a quick check.
- Stay under the cliff if you can. In Connecticut at 6.99%, the marginal cost of going over the cliff is federal tax + state tax + full PTC clawback. The break-even conversion size is smaller than in tax-free states.
- If you must go over, convert big. Once you've crossed the cliff, additional conversion dollars only cost federal + state tax (no incremental PTC loss). A "rip the bandage" conversion year can be efficient if you have many traditional dollars to move.
- Coordinate with capital gains and the 0% LTCG bracket. Connecticut taxes long-term capital gains as ordinary income at the same top marginal rate (6.99%). That stacks on top of federal LTCG (0%/15%/20%) and the 3.8% NIIT for high earners. A 'free' federal 0% LTCG harvest still costs you 6.99% at the state level — meaningful in this jurisdiction, particularly during Roth-conversion years when your MAGI is already elevated.
- Plan ahead for IRMAA. The IRMAA Medicare premium surcharge has a 2-year lookback. A Connecticut resident in their early 60s converting today will see IRMAA implications at 65. See RMD + IRMAA calculator for the lookback math.
State tax basics for Connecticut retirees
| Question | Connecticut |
|---|---|
| State income tax | 6.99% top marginal |
| Number of brackets | 7 |
| Social Security taxed | Yes (with thresholds) |
| 401(k) / Traditional IRA taxed | Yes |
| State estate / inheritance tax | Yes |
| Retirement-friendliness tier | high tax |
| Notable feature | AGI thresholds for SS exemption ($75K single / $100K MFJ), $13.61M estate exemption |
| 30-yr MC success rate (rank) | 72.35% (#43/51) |
| Median 30-yr state tax | $88,074 |
Model your full Connecticut retirement scenario
Free 10,000-path Monte Carlo with state-specific tax engine, ACA cliff, Roth conversion optimizer, IRMAA lookback — all in your browser, no signup.
Run a free simulation →Related calculators and reading
- All-states retirement tax comparison — see Connecticut alongside the other 50 jurisdictions.
- ACA Subsidy Cliff Optimizer — find the largest Roth conversion that keeps you under 400% FPL.
- Roth Conversion Optimizer — bracket-fill vs. fixed-amount strategy comparison.
- RMD + IRMAA Calculator — Medicare premium surcharge based on 2-year-old MAGI.
- Safe Withdrawal Rate Calculator — sequence-of-returns-aware withdrawal planning.
- Research: 51-State 30-year Monte Carlo (2026) — full ranking and dataset.
- Research: Monte Carlo ACA Cliff 2026 — 80,000-path study of the cliff cost.
FAQ
Does Connecticut tax Roth conversions?
Connecticut taxes Roth conversions as ordinary income at the state level. At a top marginal rate of 6.99%, a $30,000 conversion costs about $2,097 in state tax alone — on top of federal tax and any ACA subsidy clawback.
What is Connecticut's 30-year Monte Carlo retirement success rate?
In QuantCalc's 510,000-path Monte Carlo study, a representative retiree in Connecticut (age 60, $2M balance, 60/40 portfolio, $80K real spend) finished 30 years at 72.35% success rate — ranked #43 of 51 jurisdictions. Median 30-year state tax: $88,074. Median terminal balance: $824,333.
What is the ACA cliff in Connecticut for 2026?
The ACA premium-tax-credit cliff is a federal threshold, not state-specific. For a household of two in 2026, it sits at 400% of the federal poverty level — $81,760. Crossing it by even $1 of MAGI eliminates the full subsidy under the OBBBA 2026 rules.
Is Connecticut a good state to retire for tax purposes?
Connecticut is one of the higher-burden states for retirees, especially on traditional pre-tax withdrawals. Agi thresholds for ss exemption ($75k single / $100k mfj), $13.61m estate exemption. In our Monte Carlo ranking it placed #43 of 51 jurisdictions.
Does Connecticut tax Social Security benefits?
Connecticut taxes Social Security benefits as part of state income. Some exemptions or income thresholds may apply.
Does Connecticut have a state estate or inheritance tax?
Yes — Connecticut has a state-level estate or inheritance tax in addition to the federal estate tax. Plan transfers accordingly.
How does Connecticut tax capital gains?
Connecticut taxes long-term capital gains as ordinary income at the same top marginal rate (6.99%). That stacks on top of federal LTCG (0%/15%/20%) and the 3.8% NIIT for high earners. A 'free' federal 0% LTCG harvest still costs you 6.99% at the state level — meaningful in this jurisdiction, particularly during Roth-conversion years when your MAGI is already elevated.
Last updated 2026-05-16. State income tax data sourced from the Connecticut Department of Revenue and the Tax Foundation's 2026 state tax facts publication. ACA poverty-level figures from HHS 2026 Federal Register. Monte Carlo numbers from the QuantCalc 51-state research drop (2026-05-12, CC-BY-4.0). This page is educational. Not tax, legal, or financial advice — consult a qualified advisor.