Illinois has been an open-rating state since 1983: NCCI files advisory rates with the Illinois Department of Insurance, but carriers are free to set their own. That freedom cuts both ways — Illinois benefit levels are among the higher in the Midwest, and the carrier decision moves premium more than any published number.

The current rate environment in Illinois

NCCI’s most recent Illinois filing proposed an essentially flat 0.1% advisory rate decrease effective January 1, 2026. With advisory rates stable, what changes an Illinois employer’s bill is classification accuracy, the experience mod, and which carrier wants the class this year.

Where to find official Illinois rate data

Illinois does not publish free per-class advisory rates — NCCI’s tables are subscription products, and the IWCC’s insurance page explains the open-rating system. The practical checklist for Illinois employers: verify your class codes, review your mod worksheet annually, and get the account in front of carriers that actively write your class — appetite differences in Illinois are dramatic.

What determines your Illinois premium

• Class codes — every job type carries its own rate; misclassification is the most common cause of overpayment
• Payroll — premium is calculated per $100 of payroll, by class
• Experience mod — your claims history versus similar businesses scales the whole premium up or down
• Carrier pricing — Illinois carriers set their own rates entirely — NCCI advisory values are reference points, and per-class pricing varies more here than in loss-cost states
• Credits and programs — safety programs, dividend plans, and pay-as-you-go options move the net cost

How to get the best rate in Illinois

The rate tables are only the starting point: the carrier you land with, the accuracy of your class codes, and how your payroll is reported decide what you actually pay. We quote Illinois businesses across a dozen A-rated markets and show you the comparison — including pay-as-you-go billing that matches premium to actual payroll. See our Illinois workers’ comp guide and Illinois forms & resources for the rest of the picture.

Illinois rate FAQs

Who sets workers’ comp rates in Illinois?

Since 1983, each carrier sets its own rates. NCCI files advisory rates with the Department of Insurance (the 2026 filing was essentially flat at -0.1%), but insurers are free to deviate — and they do.

Why is workers’ comp expensive in Illinois?

Illinois benefit levels are comparatively generous, which flows into rates. That makes the controllables — classification, experience mod, and carrier selection — worth more in Illinois than in lower-cost states.

How do I lower my Illinois workers’ comp premium?

Verify class codes, manage claims to protect your mod, consider pay-as-you-go billing, and re-shop across carriers regularly — in an open-rating state, yesterday’s best market is often not today’s.