Connecticut Retirement Income Tax Calculator

Retirement income tax calculation for Connecticut. Social Security is taxable at the federal level if combined income exceeds $25,000 (single) or $32,000 (married) — up to 85% may be taxed. This calculator excludes Social Security benefits from the STATE-taxable base entirely (many states exempt Social Security regardless of their general income tax treatment; this is a simplifying assumption, not a state-by-state verified exclusion list). Pension and 401(k)/IRA income is state-taxable only after Connecticut's retirement exclusion below. Connecticut's pension and annuity subtraction (2025 Form CT-1040 instructions, Line 48b and its phase-out table) removes 100% of pension and annuity income and 75% of non-Roth IRA withdrawals while federal AGI is under $100,000 joint / $75,000 single, then scales the subtraction down in steps to zero at $150,000 joint / $100,000 single. Federal AGI here is the taxable Social Security plus the pension, IRA and interest you enter. The calculator applies the 75% share to the whole 401(k)/IRA box: a 401(k), 403(b) or 457(b) payout that your federal return reports as a pension subtracts in full, so enter it as pension income. Connecticut's brackets then run on the remainder; its personal exemption and income-tested credits are not applied. The IRA share used is the 75% in the 2025 instructions (the latest edition read, on 2026-10-20); if Connecticut's 2026 return allows more, the tax shown is too high, never too low. Because those deductions are left out, the Connecticut figure is an upper bound after the retirement exclusion; every filer is assumed to be 65 or older. Federal tax uses the final 2026 brackets and standard deduction from IRS Revenue Procedure 2025-32, plus the section 63(f) additional standard deduction for age 65+ — $2,050 for a single filer and $1,650 per qualifying spouse (so $3,300 when both spouses are 65+ on a joint return). It does NOT apply the separate enhanced deduction for seniors under 26 U.S.C. §151(d)(5)(C) ($6,000 per qualified individual age 65+, claimed on Schedule 1-A Part V and phased out by 6% of MAGI over $75,000 single / $150,000 joint, available for tax years beginning before January 1, 2029). If you and your spouse are both 65+ and under that phase-out, the unmodelled deduction is worth up to $12,000 of additional federal deductions, so the federal tax shown here is deliberately CONSERVATIVE (too high) rather than optimistic — use the dedicated senior deduction calculator to model it.