Illinois Tax on Capital Gains 2025 – If you live in Illinois or own assets that generate capital gains in 2025, understanding the state’s tax rules is essential. Unlike many states that offer lower long-term capital gains rates, Illinois taxes all capital gains at the same flat rate as ordinary income. This guide breaks down everything U.S. taxpayers need to know about the Illinois tax on capital gains in 2025, including the exact rate, how it interacts with federal taxes, who must pay, recent changes, and proven ways to minimize your liability.
What Are Capital Gains and How Do They Work?
Capital gains occur when you sell an asset—like stocks, real estate, cryptocurrency, or business interests—for more than you paid. The profit is a capital gain.
- Short-term capital gains come from assets held one year or less.
- Long-term capital gains come from assets held more than one year.
Federally, these are taxed differently, but Illinois treats them the same way. All realized capital gains flow into your federal adjusted gross income (AGI) and are then subject to Illinois tax rules.
Illinois Capital Gains Tax Rate in 2025
Illinois uses a flat individual income tax rate of 4.95% on all net income, including capital gains. There is no special reduced rate for long-term capital gains at the state level. Whether your gain is short-term or long-term, it is taxed at this same 4.95% flat rate.
This rate has remained unchanged since 2017 and applies fully to tax year 2025. Illinois does not offer a capital gains exclusion, deduction, or preferential treatment like some other states.
Federal vs. Illinois Capital Gains Tax: Side-by-Side Comparison for 2025
| Aspect | Federal Rules (2025) | Illinois Rules (2025) |
|---|---|---|
| Short-term gains | Taxed as ordinary income (up to 37%) | Taxed at flat 4.95% |
| Long-term gains | 0%, 15%, or 20% (plus possible 3.8% NIIT) | Taxed at flat 4.95% |
| Distinction between short/long-term | Yes | No |
| Top effective state rate on long-term gains | N/A | 4.95% |
High earners may also owe the federal 3.8% Net Investment Income Tax (NIIT) on gains above $200,000 (single) or $250,000 (married filing jointly). Illinois does not conform to or add to this federal surtax.
Who Must Pay Illinois Tax on Capital Gains?
- Full-year Illinois residents: Pay 4.95% on all capital gains, regardless of where the asset is located.
- Part-year residents: Pay on gains earned while an Illinois resident plus Illinois-source gains.
- Nonresidents: Pay only on Illinois-source capital gains (e.g., sale of Illinois real estate or tangible personal property). Nonbusiness gains from intangibles (stocks, bonds) are generally not taxed by Illinois for nonresidents.
Nonresidents and part-year residents use Schedule NR to compute the Illinois portion.
Key Changes Affecting Illinois Capital Gains in 2025
The most notable update for 2025 is a new sourcing rule for pass-through entities (PTEs):
Effective for tax years ending on or after June 16, 2025, gains or losses from the sale of shares in an S corporation or partnership interests (other than investment partnerships) are allocable to Illinois if the PTE is taxable in Illinois. The gain is apportioned based on the average of the PTE’s Illinois apportionment factor for the year of sale plus the prior two tax years. These are reported on Schedule NB.
This change primarily affects out-of-state owners of Illinois-based businesses.
No changes were made to the 4.95% flat rate or the general treatment of capital gains for individual taxpayers.
Special Rules and Exemptions for Illinois Capital Gains
- Pre-August 1, 1969 appreciation: Illinois does not tax the portion of gain on assets acquired before August 1, 1969, that accrued before that date. Use Schedule F to calculate the valuation limitation.
- Retirement-related gains: Certain capital gains on employer securities may be subtracted if reported as retirement income.
- Industry-specific surcharges: Medical cannabis organizations and gaming licensees may owe additional surcharges equal to their federal tax liability on certain gains (through 2027 for gaming).
How to Report and File Capital Gains on Your Illinois Return in 2025?
- Report all capital gains on your federal Form 8949 and Schedule D.
- Enter federal AGI on IL-1040, Line 1.
- Make any allowed Illinois modifications (rare for most capital gains).
- Compute Illinois base income and apply the flat 4.95% rate.
- Nonresidents and part-year residents attach Schedule NR.
- PTE owners may need Schedule NB for the new apportionment rule.
- File by April 15, 2026 (automatic 6-month extension available for filing, not payment).
Even if you owe no tax, file to claim refunds of withholding or estimated payments.
Real-World Example: Illinois Capital Gains Tax Calculation for 2025
Jenna, an Illinois resident, sells Apple stock held since 2019 for a $350,000 long-term capital gain in January 2025.
- Federal tax (approximate): 15% long-term rate on most of the gain + 3.8% NIIT on the portion above the threshold ≈ $50,783.
- Illinois state tax: 4.95% × $350,000 = $17,325.
Total combined tax on the gain: roughly $68,108 (before any deductions or credits). Holding the asset longer only helps at the federal level.
Proven Strategies to Minimize Your Illinois Capital Gains Tax in 2025
- Tax-loss harvesting: Offset gains with capital losses (up to $3,000 net loss against ordinary income annually; carry forward the rest).
- Hold for federal long-term treatment: Reduces federal rate even though Illinois rate stays 4.95%.
- 1031 like-kind exchanges (real estate only): Defer both federal and Illinois gains.
- Charitable Remainder Trusts (CRTs): Defer gains inside a tax-exempt trust.
- Retirement account contributions: Lower your overall taxable income.
- Move to a no-capital-gains-tax state before selling (if feasible—consult a tax advisor for residency rules).
Always work with a qualified CPA or tax professional for personalized planning.
Common Questions About Illinois Capital Gains Tax 2025 (FAQ)
Is there a lower long-term capital gains tax rate in Illinois?
No—Illinois taxes all capital gains at the flat 4.95% rate.
Do nonresidents pay Illinois capital gains tax on stock sales?
Generally no, unless the stock sale is tied to an Illinois business or real property.
Does Illinois have a capital gains exclusion?
No general exclusion, but pre-1969 appreciation and certain retirement gains may qualify for relief.
When are 2025 Illinois taxes due?
April 15, 2026, for tax year 2025.
Plan Ahead and Consult a Professional
The Illinois tax on capital gains in 2025 remains straightforward at 4.95% but combines with federal taxes to create a meaningful burden for investors and homeowners. Early planning—whether through loss harvesting, deferral strategies, or timing sales—can save thousands.
For the latest official guidance, visit the Illinois Department of Revenue website. Always consult a licensed tax advisor or CPA for your specific situation, as individual circumstances and future legislative changes can affect your outcome.
This article is for informational purposes only and is not tax advice.