Infrastructure Engineering Inc. (IEI) is pleased to be recognized on Crain’s Chicago Business 2026 List of Largest Engineering Firms highlighting the firm’s continued growth and its commitment to delivering impactful infrastructure solutions throughout the Chicago region and across the country.
Founded as a two-person office in Chicago, IEI has grown to more than 200 employees across ten offices in eight states. This milestone reflects the trust of our clients and partners, the dedication of our employees, and our continued investment in building strong communities through innovative engineering solutions. For nearly three decades, IEI has partnered with public agencies to deliver transportation, water, aviation, and municipal infrastructure projects that improve mobility, enhance public safety, expand access, and support long-term economic growth.
Being recognized by Crain’s Chicago Business is a testament to the relationships we’ve built, the projects we’ve delivered, and the talented people who make our work possible. We remain committed to helping our clients solve complex infrastructure challenges while continuing to grow strategically and serve the communities that depend on resilient infrastructure.
Read more about the rankings and IEI’s continued growth: Crain’s 2026 Largest Engineering Firms List, visit Crain’s 2026 list of the largest local engineering firms – Crain’s Chicago Business
