The Illinois Marriage and Dissolution of Marriage Act will change how courts calculate child support on January 1, 2027. The amendment updates the shared physical care formula and adds new income reporting duties. It also sets clear presumptions for incarcerated parents and parents with very low incomes.
Illinois uses an income shares model to set child support. Courts combine both parents’ net incomes and apply a statutory schedule to find a basic obligation. That foundation stays the same under the amendment. What changes is how the formula responds when both parents share meaningful parenting time.
These updates matter for parents negotiating a parenting plan in Cook or Lake County. Parenting time, income disclosure, and support often connect in a single settlement agreement. A change to one piece can shift the math on the others. Families with business income, bonuses, or other variable compensation may see the reporting rules play a larger role. Every new support order must now include an ongoing duty to share income information.
How the Illinois Marriage and Dissolution of Marriage Act Redefines Shared Physical Care
Senate Bill 3524 amends Section 505 of the Act, which governs child support. It also amends Section 510, which governs modification of support orders. Under prior law, the shared physical care formula applied when each parent had 146 or more overnights per year. The amendment lowers that threshold to 110 overnights.
Parents can reach shared care status through a court deviation from the guidelines or by agreement. The bill also recognizes overnight equivalents. A court can use this method when a parent has significant parenting time on separate days without overnight stays. That time still counts toward shared care, even though the child does not stay the night.
The calculation follows a set sequence:
The court multiplies the basic child support obligation by 1.5 to find the combined shared care obligation.
Each parent’s portion follows their percentage share of combined adjusted net income.
Each portion is multiplied by the percentage of time the child spends with the other parent.
The court applies any adjustment for parents below 146 overnights.
The two obligations offset, and the parent who owes more pays the difference.
The 1.5 multiplier and the offset method mirror the structure of the prior 146-overnight rule. The main change is which families now qualify for the calculation.
Illinois Marriage and Dissolution of Marriage Act Adjustments Below 146 Overnights
The new structure creates a middle tier for parents with 110 to 145 overnights. Public Act 104-0733 creates a statutory table to calculate support in that range. The table sets the adjustment based on the overnights or overnight equivalents a parent exercises each year.
Before this change, a parent with 140 overnights received no shared care calculation. The standard guideline amount applied, as if that parent had far less parenting time. However, the new table gives courts a structured way to account for time between 110 and 145 overnights. Parents at 146 overnights or more receive the shared care calculation without a table adjustment.
The amendment also sets a firm ceiling. After any adjustment, the shared care obligation cannot exceed the amount the basic guidelines would produce. While the shared care formula can lower an obligation, but it cannot raise one above the standard figure.
Under this structure, the overnight count in a parenting plan carries more weight. A difference of a few nights can move a parent into or out of a calculation tier. Courts and parties will rely on the plan’s schedule to determine which rule applies.
New Income Reporting and Minimum Support Rules
Senate Floor Amendment No. 1 adds an income exchange requirement to every child support order. Both parents must exchange income information each year. Either parent must also notify the other parent and the clerk of court within 10 days of certain job changes. That duty applies each time a parent starts new employment. It also applies each time employment ends for any reason.
The exchanged information must be in writing and must verify the parent’s net income. When a parent starts a new job, the notice must include the new employer’s name and address.
The amendment also addresses incarceration. A parent incarcerated for more than 180 days is presumed unable to pay any child support. That said, the other parent can rebut that presumption with evidence that the incarcerated parent can pay during incarceration.
A separate provision covers obligors with very limited income. The law creates a rebuttable presumption of a minimum of $40 per month, per child. Notably, the presumption applies when the obligor’s actual or imputed gross income is at or below the federal poverty level. Courts use the most recent U.S. Department of Health and Human Services guidelines for a family of one.
What the Illinois Marriage and Dissolution of Marriage Act Update Means for Divorcing Parents
The Illinois Marriage and Dissolution of Marriage Act amendment takes effect on January 1, 2027. It extends shared care to more parenting arrangements and gives courts a defined table for partial shared time. It also caps the result at the standard guideline amount.
The new reporting rules create an ongoing obligation after the divorce concludes. Annual income exchanges and 10-day job change notices act to keep both parents informed. Also, the clerk of court will receive notice of employment changes.
The presumptions for incarcerated and low-income parents add predictability to cases involving those circumstances. Each presumption remains rebuttable, so courts can still weigh evidence on either side.
Cook and Lake County parents building a parenting plan may benefit from reviewing how these rules apply. Overnight counts, income documentation, and support terms now connect more closely than before. Accurate records of income and parenting time support both compliance and future modification requests. To discuss how the January 2027 amendment may affect your case, contact the Chicago-based family law firm of Block | Reid.
