In re Marriage of Mulvihill, 2021 IL App (5th) 170474-U

1. Case citation and parties
- In re Marriage of Mulvihill, No. 5-17-0474, 2021 IL App (5th) 170474-U (Dec. 6, 2021).
- Petitioner-Appellee: Karen Mulvihill. Respondent-Appellant: David Mulvihill.

2. Key legal issues
- Whether the trial court abused its discretion in denying a motion to modify child support under 750 ILCS 5/510(a) for lack of a “substantial change in circumstances.”
- Whether the movant’s timing/motivation (seeking relief after statutory shift from the percentage-of-income model to the income-shares model effective July 1, 2017) and alleged voluntary business closure undermined his claim.
- Credibility/good-faith considerations when a parent alters business operations shortly before seeking modification.

3. Holding / outcome
- The appellate court affirmed the denial of David’s motion to modify child support and denial of his motion to reconsider. The court concluded the trial court did not abuse its discretion.

4. Significant legal reasoning (concise)
- Standard: modification requires a substantial change in circumstances; trial-court factual findings receive great deference and are reversed only if no reasonable person would agree (citing Connelly, Garrett).
- The trial court focused on credibility and good faith: David’s July 6, 2017 email showed he acted because of the statutory change, not an independent change in finances; he filed a certificate of assumed-name cessation days later. The court found the business closure appeared voluntary and not made in good faith to alter support.
- The movant failed to present sufficient, specific evidence quantifying a consequential net change (insufficient proof that increased Wash U income or decreased side-business income produced a substantial change under the new guidelines). The court therefore properly denied modification.
- Appellate court noted it may affirm on any basis in the record (citing Harms).

5. Practice implications for family-law practitioners
- Burden: assemble contemporaneous, granular financial evidence (paystubs, tax returns, profit/loss for business, employer confirmation of salary changes) quantifying net change since the last order.
- Timing/motive matters: courts will scrutinize sudden business closures or voluntary income reductions after a favorable statutory change; document good-faith reasons for business cessation and efforts to preserve income.
- Do not rely on a statutory rule change alone—show a substantial, provable financial impact.
- Expect deference to trial-court credibility findings; appellate reversal is difficult absent clear lack of evidentiary support.