Illinois Family Court — The IMDMA Network

750 ILCS 5 as a directed graph. Every section of the Illinois Marriage and Dissolution of Marriage Act connected by cross-references, procedural dependencies, and definitional chains.

1. The IMDMA Structure

The IMDMA is small enough to read in a weekend but dense enough to litigate for years. Unlike the IRC’s 800+ sections and ~70,000 cross-references, the IMDMA packs its complexity into definitional ambiguity and judicial discretion rather than structural sprawl.

2. The Network Graph

A force-directed simulation of the IMDMA’s major sections. Node size = in-degree (how many other sections reference it). Color = article grouping. Edges show cross-references and procedural dependencies. Drag nodes to explore the topology.

3. The Hub Sections

§503 (Property) and §505 (Child Support) are the hubs — everything flows through them. §501 (Disclosure) is the gatekeeper — nothing proceeds without financial disclosure.

Article	Sections	Covers
Part 1–4	§102, §401, §404.1	Definitions, dissolution grounds, bifurcation
Part 5 — Financial	§501–§513	Disclosure, agreements, property, maintenance, child support, attorney fees
Part 6 — Parenting	§602–§610	Decision-making, parenting time, plans, relocation, restriction, modification
Modification	§510, §610.5	Post-judgment modification of financial and parenting orders

§503 — Disposition of Property and Debts

The core property division section. Distinguishes marital from non-marital property. Courts must consider “all relevant factors” — another non-exhaustive factor list. Every financial section references §503 because you cannot calculate maintenance, support, or fees without knowing how property was divided.

Referenced by: §502, §504, §505, §508, §510, §501

§505 — Child Support

Calculates support using income shares and parenting time allocation. This section bridges the financial and parenting subgraphs — support amount depends on §602.7 (parenting time percentage) and §504 (maintenance). The most computationally intensive section: it requires inputs from at least four other sections.

Referenced by: §504, §508, §510, §602.7, §513

§501 — Disclosure Requirements

The gatekeeper node. Requires full financial disclosure (income, assets, debts, expenses) before the court can proceed on property, maintenance, or support. Without §501 compliance, the entire financial subgraph is blocked. This is the minimum vertex cut of the financial side.

Required before: §503, §504, §505, §508

§102 — Definitions

The §7701 of family law. Defines foundational terms used throughout the Act. Every section implicitly depends on §102 for the meaning of “marriage,” “child,” “court,” and other base concepts. Highest out-degree: it feeds into everything.

Referenced by: all sections (implicit dependency)

§602.7 — Allocation of Parenting Time

The hub of Part 6. Parenting time allocation drives the entire parenting subgraph and connects to the financial side through §505 (child support). Uses the “best interests of the child” standard — a 17-factor test that is simultaneously the most important and least defined concept in the IMDMA.

Referenced by: §505, §602.5, §602.10, §603.10, §610.5

§510 — Modification and Termination

The feedback loop. Allows post-judgment modification of maintenance and child support upon showing “substantial change in circumstances.” Creates a cycle: judgment → changed circumstances → modification → new judgment. Most contested motions in Cook County are §510 petitions.

Modifies: §504, §505. See also: §610.5 (parenting plan modification)

4. The Disclosure Bottleneck

Without disclosure, the entire financial side of the case is blocked. §501 is the minimum vertex cut — remove it and the financial subgraph disconnects from the rest of the IMDMA.

5. Parenting vs. Financial Subgraphs

Downstream Section	What It Does	Why Disclosure Is Required
§503 — Property division	Divides marital vs. non-marital assets and debts	Cannot divide what you do not know exists
§504 — Maintenance	Sets spousal support amount and duration	Maintenance depends on both parties’ financial circumstances
§505 — Child support	Calculates support obligation	Income shares model requires verified income
§508 — Attorney fees	Allocates fees based on financial disparity	Fee shifting requires proof of inability to pay

Financial Subgraph

§501–§510

Property division, maintenance, child support, attorney fees. Internally dense: §503 feeds §504 feeds §505, and §508 considers all three. §501 (disclosure) is the entry point. §510 (modification) creates feedback loops.

Nodes: §501, §502, §503, §504, §505, §506, §508, §510, §513

Parenting Subgraph

§602–§610

Decision-making, parenting time, plans, relocation, restriction. Also internally dense: §602.5 and §602.7 are allocated together, documented in §602.10, modifiable via §610.5. §603.10 (restriction) is the enforcement edge.

Nodes: §602.5, §602.7, §602.10, §602.11, §603.10, §607.5, §609.2, §610.5

The graph visualization makes this two-cluster structure visible. Financial nodes cluster left (blue), parenting nodes cluster right (green), with §505 and §503 pulling toward both clusters.

6. Comparison to the IRC

Dimension	IRC (Title 26)	IMDMA (750 ILCS 5)
Nodes	800+ sections	~50 sections
Cross-references	~70,000	~200
Hub section	§7701 (definitions)	§102 (definitions)
Gatekeeper	None (no prerequisite)	§501 (disclosure required first)
Undefined key term	“trade or business”	“best interests of the child” (§602.7)
Feedback loop	Tax planning → litigation → codification	Custody disputes → case law → statutory reform
Network type	Scale-free (power-law degree)	Two-cluster with bridges
Complexity source	Structural sprawl, circular definitions	Judicial discretion, factor-list ambiguity

The IMDMA’s “Trade or Business”

“Best interests of the child” is to the IMDMA what “trade or business” is to the IRC. It is the most important concept and the least defined. §602.7(b) provides a 17-factor test, but the factors are non-exhaustive, subjective, and unweighted. Judges have enormous discretion in how to balance them. Like “trade or business,” the term has massive in-degree (referenced throughout Part 6) and zero definitional resolution — an absorbing state that generates litigation because it can never be fully resolved. Every parenting case is, at bottom, a dispute over what “best interests” means for a specific child.

7. For Pro Se Litigants

The gap between the DAG and reality. The code is designed to be read top-down: dissolution → disclosure → allocation → judgment. In practice, courts handle these in parallel, and the procedural dependencies are not always enforced. Parenting plans may be litigated before disclosure is complete. Temporary orders may set support before property is divided. The gap between the code’s DAG and the court’s actual workflow is where pro se litigants get lost. The code assumes sequential processing; the court operates concurrently. If you are representing yourself, understand the DAG — then understand that the court may not follow it.

Common Traps

Trap 1: Assuming Disclosure Happens Automatically

It does not. §501 requires both parties to disclose, but enforcement requires motions. If the other side does not produce documents, you must file a Motion to Compel (Supreme Court Rule 219(c)). This costs time and money, which is exactly the point if the other side is trying to delay.

Trap 2: Conflating Parenting Time with Custody

Illinois eliminated the word “custody” in the 2016 IMDMA reform. There is now “allocation of parental responsibilities” (§602.5 for decision-making, §602.7 for time). Using old terminology in filings signals unfamiliarity with the current statute.

Trap 3: Ignoring the §505/§602.7 Bridge

Child support depends on parenting time percentage. If you negotiate parenting time without understanding its financial implications (or vice versa), you may lock in a support obligation you did not intend. The two subgraphs are not independent — §505 bridges them.

Trap 4: Missing Modification Deadlines

§610.5 requires a showing of “substantial change” and has a two-year presumption against modification for non-emergency changes. §510 modifications of maintenance are lost if you fail to petition before a deadline in the original order. The modification sections have their own procedural requirements that are easy to miss.

Which Sections to Read First

Priority	Section	Why
1	§102 — Definitions	Defines every term used in the Act. Read this before anything else.
2	§602.7 — Parenting time	The 17-factor “best interests” test. This is what the judge will apply.
3	§501 — Disclosure	Understand what you must produce and what you can demand.
4	§505 — Child support	The income shares calculation. Know how your number is computed.
5	§503 — Property division	Marital vs. non-marital property. Know the classification rules.
6	§508 — Attorney fees	Fee shifting based on financial disparity. Know your rights to contribution.
7	§510, §610.5 — Modification	Know what can change after judgment and what triggers are required.

Uncertainty

The ~200 cross-reference estimate is based on a reading of the statutory text, not a formal parse. The actual count depends on how you define a “cross-reference” (explicit statutory citations vs. implicit procedural dependencies).
The graph visualization is a model based on the author’s reading of 750 ILCS 5 and its procedural structure. It is not generated from a formal parse of the ILCS XML.
The “best interests” analysis draws on the statutory factor list (§602.7(b)) but the weighting and application of factors varies by judge, courtroom, and case. There is no algorithmic resolution.
Procedural descriptions reflect Cook County practice as of 2026. Other Illinois counties may handle case flow differently.
This page is an analytical tool, not legal advice. If you are representing yourself in Illinois family court, read the actual statute (available at ilga.gov) and consider consulting a licensed attorney for case-specific guidance.