Illinois prevailing wage rates: A contractor’s guide

Many Illinois construction projects funded by the government, even in part, are subject to state prevailing wage laws. These laws set minimum wage and fringe benefit rates to promote competitive wages for construction workers in the state. 

Noncompliance with Illinois prevailing wage legislation has real consequences. In the fiscal year 2026, the Illinois Department of Labor (IDOL) had already recovered more than $906,000 statewide in unpaid prevailing wages.

This guide helps construction companies avoid a similar fate by digging into how Illinois prevailing wage rates work. Discover how to calculate them, what contractors need to do to stay compliant, and what happens when they don’t.

What is the prevailing wage in Illinois?

Prevailing wages in Illinois set the minimum compensation contractors must pay employees engaged in public works projects. The rules appear in the Illinois Prevailing Wage Act (820 ILCS 130) and apply to a broad range of publicly funded construction projects, including demolition, repair, alteration, and maintenance work.

So, how much is prevailing wage in Illinois? IDOL sets prevailing wage rates, but there’s no universal rate that applies statewide. IDOL prevailing wages vary by county and trade classification, often including distinct straight-time, overtime, or holiday pay requirements. They might also incorporate both hourly wages and fringe benefits like health insurance or pension plans. Certain fringe benefits require tracking contributions or providing specific forms of documentation.

To find a specific prevailing wage rate, visit IDOL’s Current Prevailing Rates page, and click on the county the project is located in to view a PDF wage table. Then, scan the table to find the trade classification in question. Some classifications are split into several types, such as building (BLD) and highway (HWY), each with their own distinct rates. Others are split into classes with variable compensation levels.

For example, the base hourly wage for a Cook County carpenter on any project type is $58.51. Adding up the fringe benefit rates gives a total fringe rate of $46.82, for a full prevailing wage obligation of $105.33.

Complying with Illinois prevailing wage legislation means immediately tying the right cost code to each hour worked, paying workers correctly based on their classification, and confirming both GC and subcontractor certified payroll reports are correct before submission. Accurate payroll reporting should hold up to scrutiny.

What goes into determining prevailing wage rates in Illinois?

IDOL decides prevailing wage rates based on county, trade classification, and local collectively bargained wage standards. To stay compliant, contractors have to apply the right determination to the jobsite and the right rates to each worker based on their classification. They also need to make sure they’re working from the latest wage schedule.

Here are some of the key factors to think about when determining prevailing wage rates for a project.

County and trade classifications

The two primary factors that go into a prevailing wage rate are the county the job takes place in and the worker’s trade classification. Misclassifying either is one of the most common ways contractors end up facing penalties.

Hourly wage and fringe benefit calculations

Learning how to calculate prevailing wages in Illinois means understanding the two core components of the equation: the base hourly wage and fringe benefit obligations like health insurance and retirement plan contributions. Employers can cover fringe either through direct bona fide benefit contributions or by paying them out as additional wages.

Many classifications also come with their own overtime, weekend, and holiday rates to factor into each month’s payroll calculations. If a contractor’s payroll solution can’t keep up, it might be time to consider switching payroll providers to avoid mistakes.

IDOL prevailing wage schedules and updates

Every June, IDOL revisits prevailing wage rates for different counties and publishes the results no later than July 15th. However, IDOL can, and frequently does, publish updated rates throughout the year. In 2025, for example, Illinois saw a total of nine rate schedules.

Keeping compliant: Prevailing wage requirements in Illinois

Adhering to Illinois prevailing wage legislation means managing several layers of regulations, from subcontractors down to certified payroll reporting.

Prime contractor requirements

The responsibility for paying the correct prevailing wage rates and maintaining records falls to the prime contractor. Contractors also need to post the relevant rates at the jobsite and keep a close eye on overall project compliance.

Subcontractor requirements

Subcontractors are held to all the same standards as prime contractors. However, if a prime contractor fails to give a subcontractor written notice that prevailing wage applies, IDOL orders the prime to pay the interest, penalties, and fines the sub would have owed. The subcontractor still owes the underpaid wages themselves.

Payroll and recordkeeping requirements

Construction companies need accurate and compliant payroll systems backed up by certified payroll documentation that’s defensible if an audit or investigation takes place. That means maintaining records for at least five years from the date of the last payment. Contractors must be able to produce those records within seven business days if IDOL or the contracting public body requests it.

Certified payroll reporting requirements

Contractors and subcontractors file certified payroll reports monthly through IDOL’s Certified Transcript of Payroll portal. The report for each month is due by the 15th of the following month.

4 common prevailing wage violations and their consequences

IDOL actively enforces prevailing wage rules, and penalties affect whoever signed the certified payroll report. In one 2026 case involving Lake of Egypt Docks in Jackson County, an owner was hit with $75,000 in back wages and close to $15,000 in penalties for misclassifying eight workers, failing to pay overtime, and not filing certified payroll reports.

To avoid a similar experience, avoid making these four common prevailing wage violations.

1. Not paying the prevailing wage

The most straightforward violation is underpayment of workers. Paying less than the prevailing wage can result in owing back wages to workers and penalties to IDOL, which may be 20% of the underpayment for first-time offenses and 50% for repeat incidents. Workers also receive 2% of the penalty each month back wages go unpaid. For any following violations, this figure rises to 5%.

2. Worker misclassification

Prevailing wage pay must be tied to each hour worked. An employee might spend half of their workweek flagging and the other half cleaning up a site. Rates could differ for each, and failing to pay workers the right wage for the correct number of hours is a violation. Assigning the wrong classification to a worker can lead not only to underpayment, but also to payroll liability and increased compliance exposure if an audit or investigation turns up a mistake down the line.

3. Certified payroll reporting violations

Reports that are late, incomplete, or inaccurate can trigger audits or even enforcement actions. Failure to file a certified payroll report can result in penalties of up to $1,000 for the first violation and up to $2,000 after that. 

4. Fringe benefits and overtime miscalculations

Contractors need to make sure they offer bona fide fringe packages that properly cover the required rates. Benefits like health insurance and retirement contributions often qualify, while things like workers’ comp and gym memberships might not. If contractors prefer not to create a compliant benefit package, they can cover some or all fringe requirements via a cash equivalent. But fringe requirements also change based on worker classification, so like wages, cash rates need to tie to hours worked.

Overtime adds another layer of complexity because distinct rates apply to different counties and classifications. It’s not always as easy as applying a flat 1.5x or 2x rate.

Prevailing wage exceptions in Illinois

Not every Illinois construction job is subject to prevailing wage laws. Unlike in California or New Jersey, Illinois doesn’t have a minimum project dollar threshold for applicability. Most exceptions come down to project type and funding structure.

In general, construction projects paid for entirely using private funds don’t have to follow prevailing wage rates. But jobs that mix federal and state or local funding aren’t exempt. Contractors must pay whichever rate is higher for each trade classification: the federal Davis-Bacon rate or the Illinois rate.

Some organizations in construction-adjacent industries also fall outside the scope of prevailing wage legislation. Employers that manufacture or process materials off-site are off the hook, and the same is true of some professional service providers such as architecture and engineering firms. Transportation work is only subject to prevailing wage rules if performed by a worker on the contractor’s payroll. Contractors don’t have to pay prevailing wage rates to outside sellers or suppliers delivering materials to the jobsite.

Manage prevailing wage compliance with Miter

Prevailing wage compliance is difficult in the best of circumstances. Add in disconnected systems for payroll, certified reporting, and field tracking, and that difficulty quickly becomes unmanageable.

Construction software like Miter is designed to close the gap. When teams don’t have to cobble together information from disjointed timesheets and payrolls, errors like misclassification and incorrect rates, overlooked fringes, and botched monthly filings tend to become a lot less common.

Miter applies the right prevailing wage rates by job and classification the moment a worker clocks in, paying the higher of the worker’s base rate or the prevailing rate to keep every payday compliant without manual double-checking. The platform credits existing employer benefit contributions to protect contractors from paying twice for the same benefit. And when it’s time to send over a certified payroll report, Miter generates clean filings from timesheet and payroll data and makes it easy to send them straight to the Illinois state portal on the contractor’s behalf.