Illinois courts prioritize the child’s best interests in divorce cases, replacing “custody” with parental responsibilities (decision-making) and parenting time (schedules). Alimony, called spousal maintenance, supports a lower-earning spouse based on need and ability to pay, using guideline formulas when applicable. Decisions hinge on statutory factors under the Illinois Marriage and Dissolution of Marriage Act (IMDMA).​
Child Custody Process
Illinois eliminated traditional custody terms in 2016, focusing on joint or sole parental responsibilities for education, health, religion, and activities, plus parenting time schedules. Courts assess the child’s wishes (if age-appropriate), parents’ cooperation, mental/physical health, abuse history, and adjustment to home/school. A parenting plan outlines these, developed via mediation before hearings if needed.​
Alimony Guidelines
Courts first evaluate 14 factors like marriage length, incomes, ages, health, employability, and standard of living before awarding maintenance. For combined gross income under $500,000 (no prior support obligations), guideline amount is 33.3% of payor’s net income minus 25% of payee’s, capped at 40% of combined net. Duration ties to marriage length (e.g., indefinite for 20+ years); payments end on remarriage, death, or agreement terms.​
Key Decision Factors
Modification Rules
Both custody and alimony orders modify on “substantial change in circumstances” affecting best interests or needs, via petition with evidence like relocation or job loss. Courts re-evaluate original factors plus new ones (e.g., purpose of change). Mediation often precedes hearings; violations trigger enforcement like contempt or makeup time.​
SOURCES
[1](https://www.chiattorney.com/post/illinois-child-custody-laws-2025)
[2](https://www.divorcenet.com/states/illinois/ilfaq_06)
[3](https://www.familylawltd.com/blog/illinois-child-custody-laws/)
[4](https://www.illinoislegalaid.org/legal-information/parental-responsibilities-custody-and-visitation)
[5](https://illinoislawforyou.com/blog/14-factors-spousal-maintenance-alimony/)
