---
title: "What is the high-BAC enhancement in Illinois?"
description: "The Illinois high-BAC enhancement applies when the driver's BAC is 0.16 or higher at the time of testing. On a first-offense DUI, the enhancement adds a mandatory minimum $500 fine and a mandatory..."
url: https://chicagoduilawyer.net/faq-items/what-is-the-high-bac-enhancement-in-illinois/
date: 2026-07-08
modified: 2026-07-08
author: "Chicago DUI Lawyer"
type: faq
lang: en
---

# What is the high-BAC enhancement in Illinois?

The Illinois **high-BAC enhancement** applies when the driver's BAC is **0.16 or higher** at the time of testing. On a first-offense DUI, the enhancement adds a mandatory minimum **$500 fine** and a mandatory minimum **100 hours of community service** under 625 ILCS 5/11-501(c)(3). On a second offense, the enhancement adds a mandatory minimum **$1,250 fine** and mandatory minimum **2 days of imprisonment**. On a third offense, mandatory minimum jail rises to **90 days** and the fine to **$2,500**. The enhancement is triggered by the number itself, not by whether the driver appeared unusually impaired. Blood, breath, or urine tests all count for enhancement purposes. Testing chain-of-custody and calibration challenges become critical when BAC is near the threshold.