750 ILCS 5/504 governs maintenance, including factors in subsection (a), guideline amount and duration in subsection (b-1) when combined income is below the statutory threshold, and deviation standards when guidelines are inappropriate. Always read the current threshold amount enacted in statute.
Alimony Calculator - Illinois
State guidelines research · April 2026 · Editorial standards
Reviewed by TheLegalCalc Editorial TeamLegal disclaimer
Legal information only. Results are estimates for planning purposes and do not constitute legal advice. Laws vary by state and change over time. Always consult a licensed attorney for your specific situation.
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Illinois maintenance for divorces governed by the Illinois Marriage and Dissolution of Marriage Act appears primarily in 750 ILCS 5/504. Courts first determine whether maintenance is appropriate after...
Illinois alimony laws: what you need to know
Illinois calls post‑divorce support maintenance and analyzes it under 750 ILCS 5/504 (with eligibility gates and deviation factors that matter before you ever “run the formula”). For many marriages up to twenty years, practitioners reference Illinois’s guideline maintenance formula band as roughly 33.3% of the payor’s net income minus 25% of the payee’s net income, subject to a combined‑income cap concept commonly discussed as preventing the payee’s total income from exceeding 40% of combined net income—parallel in *shape* to New York’s post‑2016 maintenance cap conversation under Dom. Rel. Law § 236‑B, but not identical in definitions, deductions, or durational rules. Illinois also ties duration to marriage length through percentage‑of‑length heuristics for many cases (commonly summarized as something like 20% of marriage length for a five‑year marriage in guideline duration discussions—verify the exact subsection and exceptions for your marriage length band). Compared with California § 4320, Illinois maintenance can feel more “worksheet‑driven” once eligibility is established. Compared with Texas Chapter 8, Illinois maintenance is typically less narrowly gated than Texas spousal maintenance under § 8.051. Treat estimates as planning numbers for mediation memos, not a signed order.
Frequently asked questions
No. When combined gross annual income exceeds the threshold in 750 ILCS 5/504(b-1), courts determine amount and duration using 750 ILCS 5/504(a) factors without the guideline formula. Even below threshold, courts may deviate with written findings that guideline application would be inappropriate.
750 ILCS 5/504(b-1)(1)(B) provides duration percentages tied to the length of the marriage for guideline cases. Courts may adopt or deviate based on findings. Long marriages may fall in higher bands; verify current statutory text.
Modification is governed by 750 ILCS 5/510. A substantial change in circumstances is typically required, and agreements may limit modification if clearly stated. Retirement, job loss, and health changes are common themes when supported by proof.
Courts may consider earning capacity and impute income when a party is voluntarily unemployed or underemployed, consistent with statutory maintenance factors and child-support case law analogies where applicable.
750 ILCS 5/503 equitable distribution changes each spouse’s assets, liabilities, and income streams, which directly affects need and ability to pay under 750 ILCS 5/504(a). Courts avoid double counting the same dollars in property and maintenance.
Circuit courts hear dissolution of marriage actions under the IMDMA. Local divisions vary by county but apply the same 750 ILCS 5/504 standards.
Federal tax treatment depends on instrument date and modifications; many post-TCJA orders are non-deductible and non-taxable to the recipient. Illinois conformity issues should be reviewed with a tax professional when drafting.
Legal Sources & References
- Cal. Fam. Code § 4320 — California spousal support factors
- Tex. Fam. Code § 8.051 — Texas spousal maintenance
- N.Y. Dom. Rel. Law § 236-B — New York maintenance framework
- Fla. Stat. § 61.08 — Florida alimony (including post-2023 amendments such as HB 1409)
- National Conference of State Legislatures — Alimony and spousal support laws
Citations are for research and verification. Statutes, thresholds, and agency guidance change; confirm the current text with official sources or a licensed attorney in your state.
Official Government & Bar Resources
Legal Disclaimer: The results provided by TheLegalCalc are estimates for informational purposes only and do not constitute legal advice. Laws vary by state and change frequently. Always consult a licensed attorney in your state before making legal decisions.
State-specific legal disclaimer
This Illinois maintenance estimate is informational only. 750 ILCS 5/504 guideline thresholds, amounts, and durations change with legislative updates. County procedure and evidentiary rulings vary. Consult Illinois family law counsel before filing or settling.
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