Figures last verified against primary sources on . See methodology and corrections.
A $1,000 Tax Credit Saves $1,000; a $1,000 Deduction Saves $120 to $240 Federally
A $1,000 tax credit lowers a filer's tax bill by $1,000. A $1,000 deduction lowers the income the tax is figured on, so it saves only the tax on that $1,000: $120 for a single filer in the 12% bracket for 2026, $220 in the 22% bracket and $240 in the 24% bracket. The credit is worth four to eight times as much at those incomes.
Three filers, one deduction, one credit
Each filer is single, has only wages and takes the standard deduction. The figures come from TaxMath's Form 1040 engine on the 2026 rules, with the brackets from Rev. Proc. 2025-32.
| Single filer, 2026 | Taxable income | Top bracket | Income tax | A $1,000 deduction saves | A $1,000 credit saves |
|---|---|---|---|---|---|
| $65,000 of wages | $48,900 | 12% | $5,623 | $120 | $1,000 |
| $100,000 of wages | $83,900 | 22% | $13,176 | $220 | $1,000 |
| $185,000 of wages | $168,900 | 24% | $33,134 | $240 | $1,000 |
The deduction's value grows with income because each $1,000 it removes comes off the top of taxable income, in the filer's highest bracket. The credit's value does not change, because it comes off the tax after the brackets have done their work.
Two limits apply to that rule. A deduction that pushes taxable income down across a bracket edge saves part of it at the lower rate. And a nonrefundable credit cannot take the tax below zero, so a filer who owes $600 gets $600 from a $1,000 nonrefundable credit, not $1,000. A refundable credit pays out the rest.
The same $1,000 on a state return
A state deduction is worth the state's rate on the last dollars of income, which is a few cents on the dollar rather than federal rates of 12 to 24 cents.
| A $1,000 state deduction, 2026 | At $65,000 of wages | At $185,000 of wages |
|---|---|---|
| Illinois, flat 4.95% | $50 | $50 |
| California | $80 | $93 |
| New York | $54 | $59 |
Illinois taxes every dollar of net income at one rate (Illinois DOR), so a deduction is worth the same $50 at both incomes. California and New York have graduated rates, so the deduction is worth more on the higher income, though the difference between the two incomes is small next to the federal one.
A $1,000 state credit, like a federal one, is worth $1,000 to a filer whose state tax is at least that large. The $65,000 filer owes Illinois $3,073 and California $1,975, so a $1,000 nonrefundable credit would be used in full in both.
How federal and state breaks stack
Whether a federal break also lowers the state bill depends on where it sits on Form 1040 and where the state return starts.
- A federal adjustment to income, such as a traditional IRA deduction, lowers adjusted gross income. Form IL-1040 begins with federal AGI (IL-1040 instructions), so a $1,000 IRA deduction saves the $65,000 filer $120 federally and $50 in Illinois, about $170 in all.
- The same deduction in Pennsylvania saves only the federal $120, because Pennsylvania lists the IRA deduction among federal adjustments with "No provision" in its own law (PA DOR).
- A federal credit comes off federal tax after AGI and taxable income are set, so it never changes the state return. A $1,000 federal credit is worth $1,000 federally and nothing on the Illinois return.
- A state credit comes off state tax only. Some states figure theirs as a share of a federal credit, as most state earned income credits do, but the state pays it out of its own tax.
Put the two side by side for the $65,000 filer in Illinois: a $1,000 federal credit is worth $1,000, and a $1,000 federal adjustment is worth about $170 across both returns. The credit still wins by a wide margin. The deduction is the one that reaches the state return.
Sources
Ordered by authority — the law and the agencies administering it first. Every link is checked for rot; see all sources.
- Government2025 Form IL-1040 instructionsIllinois Department of Revenue · checked 2026-10-21A resident files if required to file a federal return, or if Illinois base income exceeds the exemption allowance ($2,850 per person for 2025).Other articles citing this source
- GovernmentIncome tax ratesIllinois Department of Revenue · checked 2026-09-01The current individual rate (4.95%, effective July 1, 2017) and the corporate 7% plus the 2.5%/1.5% personal property replacement tax.Other articles citing this source
- GovernmentRevenue Procedure 2025-32 — tax year 2026 inflation adjustmentsInternal Revenue Service · checked 2026-10-20The revenue procedure itself: the §1(j)(2) rate tables with their formula rows, the capital-gains thresholds, the child tax credit amount, the §4.14 standard-deduction rows and §63(f) aged/blind additional amounts, and the §2 background listing which OBBBA sections changed each figure.Other articles citing this source
- GovernmentPA Personal Income Tax Guide — Deductions and CreditsPennsylvania Department of Revenue · checked 2026-10-21Pennsylvania allows a yearly deduction for IRC §529 contributions equal to the annual federal gift tax exclusion (IRC §2503(b)) per beneficiary, per taxpayer. Its table of deductions allowed in arriving at federal AGI but not for Pennsylvania lists "IRA deduction" and "Student loan interest deduction", each with "No provision".Other articles citing this source