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Northern Illinois University
College of Law
David C. Shapiro Memorial Law Library

Basic Legal Research

Key Illinois Statutes Related to Agencies

  • Illinois Administrative Procedure Act, 5 ILCS 100/1 to 100/15-10
    • Governs administrative processes
  • Regulatory Sunset Act, 5 ILCS 80/1 to 80/14
    • Allows for expiration of agency/act unless legislature acts to extend the time frame
  • Enabling statutes (per agency)
    • Statutes enacted to create, and give authority to, an agency

Illinois Administrative Code

After a rule/regulation is proposed and subsequently adopted, it is codified within the Illinois Administrative Code, which is a subject compilation of all codified rules/regulations promulgated by agencies within the state of Illinois. All rules/regulations for a particular state agency are codified under the same title, but subdivided into many parts and sections. 

The Illinois Administrative Code is available online from various sources. However, there is no official online or print version.



Illinois Register

Illinois Register cover imageThe Illinois Register is published weekly by the Secretary of State and contains proposed and adopted rules of Illinois state agencies.

  • In print: The print version is the only official version. KFI 1234 .A2 I433 (current & previous year in Illinois Collection, older years in South Wing or storage)
  • Online (none of the online versions are official):


Updating Illinois Administrative Regulations

While the online version of the Illinois Administrative Code is not considered official, it is kept very up-to-date and can be used to identify recent changes to a code section.

1. Determine the revision date of a code section.

The revision date can be found at the end of the code section. Example:  at the end of Ill. Admin. Code tit. 32, §33.20 (2016) you would see: (Source: Amended at 32 Ill. Reg. 9247, effective June 13, 2008).

2. Go to the cumulative Illinois Register Sections Affected Index for the current year.

This file is in PDF format and is linked from

Scan through the file for the relevant code section. Entries appear in this format:

Title 32
320.20     am     (P-13354:A-17376)

  • Title 32 is the title of the Illinois Administrative Code under which the listed sections fall.
  • 320.20 - specific section within Title 32
  • am - abbreviation for "amendment to existing section"
  • P - abbreviation for "proposed rule"
  • A - abbreviation for "adopted rule"
  • Numbers following P and A - the page numbers within the Illinois Register where the text of the rule can be found

A complete list of the abbreviations used in the Sections Affected Index is on the first page of the document.

3. Locate the appropriate issue & page of the Illinois Register in print or online.

Read the agency action or the text of the proposed or adopted rule.

Note: Since the Illinois Administrative Code is updated so quickly online, you may find that the change listed in the Sections Affected Index has already been incorporated into the text of the code section.

It is still imperative that you always update the code section to be sure you are aware of any recent changes.

Illinois Agency Decisions

Locating state agency decisions is not always easy. Some agencies provide decisions and orders on their websites. Sometimes these are searchable, but at other times specific information may be needed to locate the materials (e.g., a case name or docket number).

  • The major legal information vendors (Lexis, Westlaw and Bloomberg) also offer access to state agency decisions.
  • If an agency does not provide access to decisions on its website and its decisions are not in the legal information vendors' sites, then you need to contact the agency directly to obtain the necessary documents.
  • Even if an agency does not provide decisions on its website, it may contain procedure manuals, contact information and other useful information.
  • A searchable list of state agencies is available at or see our Libguide's alpahabetical list of State Agencies, Boards and Commissions.

The list below is a non-exhaustive list of state agencies. The availability of decisions on its website, and/or on Lexis or Westlaw, is indicated for each agency. (Bloomberg's collection of agency materials is not as extensive. Click on the Illinois scope note under "State Regulatory and Administrative" for more information.)

Related Topics

Administrative Law and Regulations

Libguide list of State Agencies, Boards and Commissions


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