Prevailing Wage Illinois: Two Laws, Monthly Filing, and County Rates

Last Updated: August 2026

Most states hand contractors one prevailing wage statute to learn. Illinois hands them two. The Illinois Prevailing Wage Act governs construction on public works, while the Illinois Procurement Code covers certain services on state contracts. Which law applies depends on the work you perform.

Illinois also runs on a monthly rhythm that catches contractors coming from other states. Certified payroll is filed every month through the Illinois Department of Labor rather than weekly, and missing that deadline carries its own civil penalty.

This guide covers who is covered, how rates are set and where to find current ones, your certified payroll obligations through the IDOL portal, fringe benefit math, apprenticeship rules, and what enforcement looks like when something goes wrong.


Not working in Illinois? Our state-by-state guide to prevailing wage and certified payroll reporting covers requirements wherever you operate.

 

Table of Contents

Illinois Prevailing Wage Basics: The Act and The Procurement Code

Illinois prevailing wage law for construction lives in the Illinois Prevailing Wage Act, 820 ILCS 130, the state's version of a "little Davis-Bacon" statute. It is administered and enforced by the Illinois Department of Labor (IDOL), which sets rates, receives certified payroll, investigates complaints, assesses penalties, and maintains the debarment list.

The Act requires that laborers, workers, and mechanics on public works be paid no less than the general prevailing rate for work of a similar character in the locality where the work is performed. Locality means the county. The rate includes hourly cash wages plus fringe benefits, and the obligation runs through every tier of the contractor chain.

Two points IDOL fields constantly. Union affiliation does not matter: the prevailing rate applies regardless of signatory status. A collective bargaining agreement is not a defense in either direction: a lower CBA rate does not reduce what you owe, and a higher one still binds you under your own contract.

The Illinois Procurement Code

Under 30 ILCS 500/25-60, prevailing wage also applies to service employees on state contracts, with separate IDOL calendar-year rate schedules for janitorial cleaning, window cleaning, food service, security, and printing. This is a narrower trigger: the Procurement Code reaches state contracts, while the Prevailing Wage Act reaches public works funded by the state or any of its political subdivisions.

 

construction workers working with rebar on site

What Counts as Public Works?

Public works means all fixed works constructed or demolished by a public body, or paid for wholly or in part out of public funds, including projects financed with bonds, grants, or loans made available by or through the State or its political subdivisions. Public body is broad: the State, every county, city, village, township, school district, and other political subdivision, plus any institution supported in whole or in part by public funds.

Three coverage rules catch contractors out:

  • Maintenance counts, at the same rate as construction, including repair, assembly, and disassembly of equipment whether owned, leased, or rented.
  • Transportation to and from the site counts, including when equipment is driven rather than hauled. Transport by sellers or suppliers does not, and neither does manufacturing or processing materials or ordinary commuting.
  • Sole proprietors and partners count. Certified payroll must include everyone performing services on the project, whether labeled employee, shareholder, partner, or member, and each must be paid the prevailing wage.

There is no dollar threshold. Unlike Ohio, Rhode Island, or federal Davis-Bacon, Illinois sets no minimum contract value. If it is covered public works, the rates apply from the first dollar.

Who Is Not Covered

The exemption list is short:

  • Work done directly by a public utility company. Note the limit: construction by a third party contracted by a public utility in public rights-of-way is covered.
  • Owner-undertaken projects at an owner-occupied single-family residence, or an owner-occupied unit of a multi-family residence.
  • Soil and water conservation work on agricultural lands by the owner or a person with legal control of the land.

Beyond these, assume coverage. If a project's status is unclear, confirm with the awarding public body in writing before you bid.

two construction workers reviewing plans on a tablet
Springfield, IL government building

Illinois Prevailing Wage vs. Federal Davis-Bacon

The Illinois Act governs state and locally funded public works. The federal Davis-Bacon Act governs federally funded or federally assisted projects, and Illinois historically stepped aside where a project required a determination from the U.S. Secretary of Labor.

That boundary has moved. Illinois prevailing wage now also reaches federal construction projects administered or controlled by a public body where the Illinois rate equals or exceeds the federal determination for the same locality and construction type. IDOL maintains a dedicated FAQ on this.

On mixed-funding projects, map your trades against both schedules before payroll runs. Classifications do not always align between the two systems.

How Illinois Prevailing Wage Rates Are Determined

There is no single dollar figure for "the Illinois prevailing wage." Rates are specific to the county, the trade or craft classification, and whether the worker is a journeyman or an apprentice.

The Annual Determination

Under Section 9 of the Act, IDOL investigates and ascertains the prevailing rate of wages for each county in the state during the month of June each year, and publishes the resulting schedule on its official website no later than July 15. That published schedule governs work performed on or after its effective date.

If IDOL revises a rate mid-year, the revised rate applies to the contract, and the public body is responsible for notifying the contractor and each subcontractor. IDOL also periodically adjusts classification boundaries. A public body discharges its duty to notify by inserting a written stipulation in the contract stating that rates are revised by IDOL and available on the Department's website. That counts as proper notification. In other words, you may never receive an active alert that a rate changed, which is why checking the schedule on a recurring basis matters.

How the Rate Is Set

The prevailing rate is the rate paid under collective bargaining agreements between employers or employer associations and bona fide labor organizations for each craft in the locality, provided those employers employ at least 30 percent of the workers in that trade in that locality.

If no such agreement exists in a locality, IDOL determines the rate for the same or most similar work in the nearest and most similar neighboring locality where agreements do exist. If a hearing establishes that fewer than 30 percent of workers in a trade receive a collectively bargained rate, the prevailing rate becomes the average wage paid in the locality over the preceding twelve months.

Any affected person may object in writing to a published determination within 30 days. Work continues at the published rate while an objection is pending.

Where to Find Current Illinois Prevailing Wage Rates

Current construction rates are published by county on the IDOL current prevailing wage rates page. IDOL also maintains a searchable prevailing wage database.

If a rate sheet looks unfamiliar when you open it, our breakdown of how to read a wage determination walks through each classification and rate line.

 

County Coverage Across Illinois

Rates are set for each of Illinois' 102 counties and vary meaningfully between them. Contractors working in the Chicago metropolitan area routinely deal with different schedules in Cook, DuPage, Lake, Will, and Kane counties on projects a few miles apart. Downstate contractors face the same across counties like Sangamon, Peoria, Champaign, and Winnebago. If your crews cross county lines, county-level rate tracking is not optional.

Illinois Prevailing Wage Compliance, Simplified

Between county rates that shift, filing certified payroll every month, and keeping records that hold up five years later, Illinois carries a real administrative load.

WageIQ automates prevailing wage and union calculations so the right rates land on every worker before payroll runs.

Prefer to skip the monthly grind altogether? Our Managed Service team generates your reports and manages your IDOL submissions on deadline, every month.

Request a demo to find the right fit for your projects.

Illinois Certified Payroll Reporting Requirements

The Act creates two separate obligations, and IDOL is emphatic that meeting one does not satisfy the other: a certified payroll alone does not substantiate compliance. You must keep the underlying records too.

Records must be kept for five years from the last payment on the contract or subcontract. For each worker: identifying details including gender, race, ethnicity, and veteran status; classification and skill level; gross and net wages per pay period; daily hours with start and end times; hourly wage, overtime, and fringe rates; and the name, address, sponsor, and administrator of each fringe benefit fund.

The certified payroll is a copy of these records minus the daily start and end times. Records may be paper or electronic, and must be available for inspection in Illinois on seven business days' notice.

Every certified payroll carries a signed statement that the records are accurate, that each worker was paid at least the prevailing rate, and that the submitter understands a knowingly false filing is a Class A misdemeanor. A general contractor may rely on a subcontractor's certification unless it knows the certification is false.

Post the county rates on site where workers can access them. Alternatively, a contractor with a business location workers regularly visit may post current rates for each county where it is working, or give each worker written notice of the project rates. Failing to post is itself a violation. You must also insert a written stipulation requiring the prevailing rate into every subcontract and project specification, and subcontractors must do the same down the chain.

Notice failures shift money, not duty. If a public body fails to give proper written notice, IDOL orders the public body to cover interest, penalties, or fines the contractor would have owed; if a contractor fails to notify a subcontractor after being properly noticed itself, the contractor absorbs them. The obligation to pay prevailing wage and back wages always stays with the employer.

Illinois requires certified payroll monthly, not weekly. The certified transcript for a given month is due no later than the 15th of the following month, and you file only for months in which construction actually occurred. Filings go to IDOL's electronic database rather than to the public body in charge of the project, except where a state agency opts to receive them directly and forward the data to IDOL.

Illinois Prevailing Wage Forms

 

 

Certified Transcript of Payroll, the Illinois certified payroll form, filed monthly, along with the CTP affidavit and instructions

 

 

 

 

Fringe Benefit Affidavit, required where you are crediting fringe contributions

 

 

 

Form WH-347, the federal certified payroll form, filed weekly on federally funded or assisted projects. It does not substitute for the Illinois form on state-funded work, so mixed-funding projects generally require both.

 

The IDOL Certified Transcript of Payroll Portal

Illinois certified payroll is filed electronically through IDOL's Certified Transcript of Payroll Portal, created under Public Act 100-1177 and Section 5.1 of the Act.

Getting set up takes two steps:

  1. Create an Illinois Public ID account at accounts.illinois.gov. IDOL recommends using a shared business email address and a business-oriented username rather than an individual's personal account, since the account will outlast any one employee's tenure.
  2. Log in to the Certified Transcript of Payroll Portal, select "Public Account," and use the credentials you just created.

For contractors filing at volume, IDOL publishes an Excel template for bulk CTP import, updated as of July 2025, along with recorded training webinars. Questions go to dol.certifiedpayroll@illinois.gov.

Apprenticeship on Illinois Prevailing Wage Projects

Apprentices must be enrolled in a program registered with the U.S. Department of Labor's Office of Apprenticeship. Registration is what makes a reduced rate legitimate. A worker who is simply new, or training informally on the job, is not an apprentice for prevailing wage purposes and must be paid the full journeyman rate.

One rule surprises contractors: an apprentice's fringe benefit package may not be lower than a journeyman's. Apprentice status reduces the cash wage component, not the fringe obligation. If you have been prorating apprentice fringes, review the calculation.

Maintaining proper apprentice-to-journeyworker ratios on site matters as well. Misclassifying workers as apprentices to cut labor costs carries the same exposure as straight wage underpayment.

 

Violations, Penalties, and Debarment

Illinois penalties run in three directions at once: money to the worker, money to the Department, and loss of access to public work.

A worker paid below the prevailing rate has a right of action for the difference plus costs and attorney's fees. The contractor also owes IDOL 20 percent of the underpayment, and owes the worker punitive damages of 2 percent of that penalty per month while it goes unpaid. On a second or subsequent action, those rise to 50 percent and 5 percent per month. Actions must be brought within five years.

A civil penalty payable to IDOL of up to $1,000 for a first offense and up to $2,000 for a second or subsequent offense within five years. Critically, each month in which a violation occurs is a separate offense, so a year of neglected filings is not one penalty. Findings can be challenged within 10 business days. Technical problems that blocked a good-faith filing attempt count as mitigation; not knowing the requirement existed expressly does not.

Willfully failing to file, filing a payroll false as to any material fact, or willfully failing to keep or produce required records is a Class A misdemeanor.

IDOL publishes a list of violating contractors at least quarterly. Two violations within five years puts you on it, and no contract may be awarded for four years from publication. That bar extends to any firm, corporation, partnership, or association in which the debarred party holds an interest, which closes the reorganize-and-rebid workaround. A conviction under the certified payroll or recordkeeping sections triggers automatic four-year debarment with no hearing.

 

Retaliating against a worker who files a complaint or testifies carries a $5,000 penalty per violation, joint employers can be held liable, and a contract awarded without meeting prevailing wage prerequisites is void as against public policy. Complaints may be filed by workers, competing contractors, unions, or the public.

Cook County and Chicago

Contractors in the Chicago area navigate more overlapping requirements than anywhere else in Illinois. A single project can sit inside Cook County, the City of Chicago, a township, and one or more special districts at once, each with potential obligations layered on top of the state Act. Cook County rates also tend to run higher than much of downstate, which affects bid math and fringe budgeting.

State prevailing wage compliance is the starting point in Chicago, not the finish line. Identify every applicable jurisdiction during the bid phase, before requirements surface mid-project.

female worker focused on her desktop computer in office

Best Practices for Illinois Prevailing Wage Compliance

  • Before bidding, confirm the funding source and which law applies: the Prevailing Wage Act, the Procurement Code, Davis-Bacon, or a combination.
  • Pull the current IDOL rate schedule for every county your crews will work in, and recheck on a schedule. Notice of a revision may be nothing more than a contract stipulation pointing at a website.
  • Calendar the filing for the 15th of every month, and file only for months construction occurred. Each missed month is a separate penalty.
  • Keep the underlying records for five years. The certified payroll does not satisfy that obligation on its own.
  • Verify every apprentice is in a registered program and that apprentice fringes are not below journeyman levels.
  • Post current county rates on site at project start, and put prevailing wage stipulations in every subcontract.
  • Document every fringe contribution you plan to credit, including plan terms and the calculation.
  • Budget compliance administration into your bid alongside wages and fringes.

Managing Prevailing Wage Compliance on an Illinois Public Works Project?

Illinois adds a wrinkle most states do not. Certified payroll has to be filed every month through the Illinois Department of Labor, on top of tracking rates that shift county by county.

WageIQ keeps the rate side under control, automating your prevailing wage and union calculations so every monthly cycle starts with accurate numbers. Prefer to skip the monthly grind altogether? Our Managed Service team generates your reports and manages your IDOL submissions on deadline, every month.

 

Illinois Prevailing Wage FAQs

The minimum hourly cash wage plus fringe benefits that must be paid to laborers, workers, and mechanics on public works projects under the Illinois Prevailing Wage Act, 820 ILCS 130. Rates are set by the Illinois Department of Labor and vary by county and trade classification.

There is no single rate. The amount depends on the county, the trade classification, and whether the worker is a journeyman or registered apprentice. IDOL publishes current rates by county.

Identify the county and classification, then apply the published total hourly determination. Allowable fringe contributions offset that total, and anything not covered by fringes must be paid in the base hourly wage. Fringe credits are annualized by dividing the annual contribution by 2,080 hours.

Monthly. The transcript for a given month is due by the 15th of the following month through IDOL's Certified Transcript of Payroll Portal, and only for months in which construction occurred.

Five years from the last payment on the contract or subcontract. Submitting certified payroll does not satisfy this; the underlying records must be kept separately.

IDOL investigates each June and publishes the annual schedule by July 15. Rates may be revised mid-year, in which case the revised rate applies to the contract.

Underpayment costs back wages plus 20 percent to IDOL and 2 percent monthly punitive damages to the worker, rising to 50 percent and 5 percent on a second action. Failing to file certified payroll carries up to $1,000 for a first offense and $2,000 for subsequent ones, with each month a separate offense. Two violations in five years means four-year debarment.