What actually happens to a bonus in Connecticut for 2026: the federal 22% supplemental withholding, Connecticut's own withholding on top — and, shown separately because they are not the same thing, the tax the bonus really owes at filing.
The year-to-date line matters only near the top: once a year's supplemental wages pass $1,000,000, the excess MUST be withheld at 37%, not 22%.
Of the $20,000 bonus, after $5,740 of withholding.
| Federal withholding | $4,400 |
| 22% flat supplemental rate | |
| Connecticut withholding | $1,340 |
| Connecticut flat supplemental rate (6.7% — IP 2026(1) Table C) | |
| Total withheld | $5,740 |
| Actual federal tax the bonus adds | $4,764 |
| Actual Connecticut tax the bonus adds | $1,200 |
| Actual tax on the bonus | $5,964 |
Withholding runs $224 LIGHT: at filing, roughly this much more is due on the bonus (before other adjustments). The 22% flat rate under-withholds anyone whose marginal bracket is higher.
The IRS lets employers withhold on separately-paid supplemental wages at a flat 22% (Publication 15 §7) — a collection rule, not the tax. At filing the bonus is ordinary income in your top brackets; the 22% is credited against the real bill, and the difference is refunded or owed. Every "bonus tax rate" headline that stops at 22% is describing the prepayment.
Source: IRS Publication 15 (2026) §7; Topic 751.
Connecticut is one of the only states whose employer guide publishes a supplemental table (IP 2026(1), Table C): bonuses are withheld at 3% when annual wages are $100,650 or less and 6.7% above that (employees expecting wages over the line can notify their employer to use 6.7% throughout). This page applies the official rate.
Source: CT DRS IP 2026(1), Table C.
Bonuses are wages for Social Security and Medicare: 6.2% until your year's wages pass the $184,500 wage base, 1.45% Medicare throughout (plus 0.9% at high incomes). Payroll usually applies it automatically; it is excluded from this page's withholding comparison because it is a tax in itself, identical either way — the paycheck calculators in this family show it in the full picture.
Source: IRS Publication 15 (2026); SSA 2026 wage base.
No — it is WITHHELD at 22% federally when paid separately. The tax itself is your marginal rate(s) on that income, settled on your return. This page shows both numbers, which is the honest way to look at it.
State withholding (where it applies) and FICA come out too — and if the bonus is paid WITH a regular paycheck rather than separately, your employer may use the aggregate method federally as well, which withholds more up front. The annual outcome is the same either way.
The excess over $1,000,000 of supplemental wages in the year must be withheld at 37% — enter earlier bonuses in the year-to-date field and the split is applied exactly.
Yes — a revised Form W-4 (extra withholding per pay period) is the standard tool when the 22% flat rate under-withholds for your bracket, which it does for most higher earners.
Connecticut Bonus Tax Calculator for 2026: a $20,000 bonus on a $120,000 salary is withheld $4,400 federally (22% supplemental) and $1,340 by Connecticut — you receive $14,260 now, and the page shows the tax actually owed at filing beside it.
100% free · No sign-up · No daily limits · No watermarks · Processed in your browser — files never leave your device
How a bonus is treated in Connecticut for 2026: the federal 22% supplemental withholding, the state layer, what lands in your account — and what the bonus truly adds to the year's tax.
On the defaults ($120,000 salary, $20,000 bonus, single), $5,740 is withheld and $14,260 received; the bonus's actual tax is $5,964.
Withholding is a prepayment set by collection rules; the tax is your marginal rate. The two coincide only by accident.
On the default figures, $14,260 of $20,000 after withholding — run your own salary and bonus for your number.
The 22% is federal only; state withholding and, in the pay packet, FICA come on top.
What is missing, broken, or could be better on this tool? Tell us — we read every suggestion.
✅ Thanks — your suggestion has been received. Suggestions like yours shape what we build next.