How to Find and Cite Illinois Law

Before 1993, the paragraph numbers in an Illinois statute cite came from a private publisher, not from the legislature. The state stopped maintaining its own arrangement after the revision of 1874. So when a new act passed, someone at a publishing house decided which chapter it belonged in, and picked its paragraph number.

Publishers disagreed with each other. The same act could land in one chapter in one edition and a different chapter in another, with different numbers either way. In the 1930s the state bar told its members to all buy one edition. That fixed the confusion. It also handed a single publisher a copyright claim over the arrangement of Illinois law. Two bills to make that arrangement official and public got vetoed, in 1987 and again in 1988.

What 1993 actually did

In 1989 the General Assembly told the Legislative Reference Bureau to plan a real codification. The Bureau's revised plan proposed folding roughly two thousand acts into 67 chapters under 9 topic areas. Public Act 87-1005 told it to go file the thing, which it did on September 14, 1992. The result is the Illinois Compiled Statutes, and it took effect January 1, 1993.

Two details matter more than the date. The compilation is official, made by the state, and entirely in the public domain, so anyone may publish Illinois statutes. And it was a reorganization only. No text of any act was changed.

Reading an ILCS number

Take 105 ILCS 5/17-3. Chapter 105 is Schools. Act 5 within that chapter is the School Code. And 17-3 is the School Code's own section 17-3, lifted straight from the act rather than assigned by anyone.

Chapters run in hundreds by topic, in steps of five, so an unfamiliar cite still tells you something. 750 ILCS 60/201 is in the 700s, which is Rights and Remedies, before you look anything up.

The old numbers are still on the page

Every compiled section carries its former address at the top. Open 720 ILCS 5/7-5 and the text starts with a note reading "from Ch. 38, par. 7-5".

Sometimes the tail survives the move. 735 ILCS 5/3-106 used to be ch. 110, par. 3-106. Sometimes nothing survives: 760 ILCS 70/2 used to be ch. 32, par. 439.51. The Bureau also publishes a 1992 Illinois Revised Statutes to ILCS cross-reference table, and one running the other way.

The old citation form keeps its year inside the cite, with a pilcrow for the paragraph: Ill. Rev. Stat. 1989, ch. 38, ¶ 7-5. Older volumes use a section symbol instead, and you keep whichever one the volume used.

And the Supreme Court's style manual tells you not to translate, which is the opposite of what most people assume. Unless the modern number is relevant to the discussion, you cite the old volume and leave the ILCS number out of it.

The compilation is an arrangement, not the law

The court's manual says it plainly. The ILCS establishes an organizational scheme only. It doesn't replace the General Assembly's practice of passing titled public acts, so the ILCS designation is for citation purposes.

Which means the public act in effect on the day of the conduct is the governing law. That's the reason an old case needs the old volume: the act that governed in 1989 may not survive anywhere in the current compilation.

It also drives a writing rule that trips up out-of-state lawyers. An ILCS number can't do any work in a sentence. You write "section 12-1 of the Criminal Code of 1961" in your text and park 720 ILCS 5/12-1 in parentheses or in a sentence of its own.

Two more things follow from the same fact. Not every public act gets compiled, since appropriations and land conveyances stay out. And the General Assembly's own website says its version is not the official text and should not be cited as authoritative. To know the current law, it says, go check the public acts.

So when the conduct is from 2014 and the section has been amended twice since, which text are you reading? If you opened the compilation today, the current one.

Rules live in a separate book with dates attached

Agency rules go into the Illinois Administrative Code. The Secretary of State codifies it under the Administrative Procedure Act, and the Joint Committee on Administrative Rules reviews what agencies file. Proposed and adopted rules run weekly in the Illinois Register, which has been going since 1978.

Rules sort into titles, parts, subparts and sections. A part cites as 1 Ill. Adm. Code 100. A section cite needs date information: 1 Ill. Adm. Code 100.500 (1998).

That date requirement isn't fussiness. The Code holds only the current version of a rule, and every earlier version lives back in the Register. In running text you name the title, not the book, so it reads "Section 527.600 of Title 77".

What Illinois holds

Illinois runs 130,401 sections of primary law. Statutes are the biggest piece at 72,251, then 55,944 regulation sections, 1,451 attorney general opinions, 426 court rules, 170 constitutional provisions and 159 agency guidance documents.

Of the statute sections, 68,485 are in force and 3,766 are repealed, still sitting in the compilation under their own numbers. All 55,944 regulation sections read as current, which is not luck. That's the Administrative Code doing what it says it does and carrying one version of each rule.

A worked example

Someone hands you Ill. Rev. Stat. 1989, ch. 38, ¶ 7-5 out of an old brief.

Read the year first, because that is the law that governed. Then find the modern number. The Bureau's cross-reference table will do it, and so will opening 720 ILCS 5/7-5 and checking that its source note points back at ch. 38, par. 7-5. Read the current text next, and expect drift. That section picked up three separate public acts in 2021.

Then cite it the way the court wants: the 1989 volume, year included, with the modern number left out unless the change is part of your argument.

What trips people up

Chapter numbers are not decoration. 720 ILCS 5/ is the Criminal Code and 735 ILCS 5/ is the Code of Civil Procedure. Both are Act 5, in different chapters.

A section can show more than one version at once when two public acts amend it in the same session. The compilation prints each with its derivation, and 5 ILCS 70/6 governs how they combine.

And a year in parentheses at the end of an ILCS cite is a publication year. It marks a printed edition, not an as-of date for the law. An edition can carry acts that had not taken effect when it shipped.

Facts used

All Illinois corpus counts below are from Vaquill AI's US primary law data, measured 2026-09-18.

Priyansh Khodiyar

Co-Founder & CTO

Priyansh leads engineering and AI at Vaquill, from the matter workbench to drafting, document comparison, document matrix, and citation-verified research.