Mechanical Engineer Salary in Illinois

Two distinct labor markets in one state

The Bureau of Labor Statistics Occupational Employment and Wage Statistics tables for Illinois, May 2024 release, report a state annual mean wage of $106,210 for 9,100 employed mechanical engineers under SOC 17-2141. The state ranks 19th nationally on nominal pay. The state-level number conceals two structurally different labor markets: the Chicago metro corporate and consulting cluster (employing roughly 6,800 of the 9,100 state MEs) and the downstate industrial cluster (Peoria, Rockford, the Quad Cities, central Illinois) employing the remainder.

Chicago's ME labor market resembles a smaller, lower-cost Houston in industry mix: corporate headquarters of large industrial firms (Boeing moved its HQ from Chicago to Arlington in 2022 but retains substantial Chicago engineering presence; Caterpillar maintains Deerfield HQ; AbbVie is in North Chicago; Abbott Laboratories in Abbott Park), a deep consulting base (Sargent and Lundy in power engineering, Burns and McDonnell, Black and Veatch IL operations), and a strong pharma and medical device cluster. Boeing Chicago's commercial airplane engineering and defense engineering teams employ several hundred MEs even after some headquarters functions moved to Arlington.

Downstate, Caterpillar is the single dominant employer. The Peoria headquarters and the Mossville Engine Development Center together employ several thousand engineers, with mechanical engineers covering engine development, hydraulic systems, drivetrain, structures, materials, and emissions engineering for the full Caterpillar product line (mining trucks, off-highway construction equipment, marine engines, gas turbines, locomotive engines). The Caterpillar concentration makes the Peoria market the largest single-site concentration of heavy-equipment MEs in North America.

Caterpillar Peoria: heavy equipment engineering at scale

Caterpillar Inc. operates a sprawling engineering footprint in the Peoria metro, with the headquarters function (after the 2017 move from Peoria proper to Deerfield) coexisting with the Mossville Engine Development Center, the Mapleton Foundry, the East Peoria proving ground, and the Edwards demonstration site. The Mossville facility is the company's largest single engineering campus and the focal point for heavy-duty engine development (off-highway diesels from 30 to 250 liters of displacement, the company's gas turbine line, and emissions technology).

Caterpillar pay bands for mechanical engineers in Peoria run roughly $72,000 to $85,000 base for new-graduate ECDP rotational hires, $90,000 to $115,000 for mid-career engineers (years 5 to 10), and $115,000 to $150,000 for senior and staff levels. The company offers an annual short-term incentive (typically 7 to 18 percent of base for mid and senior engineers tied to corporate and segment performance) and an RSU program at senior and above. Caterpillar's defined-benefit pension plan was closed to new entrants in 2003 for most US salaried employees, with grandfathering rules for engineers hired before that date.

The Peoria cost of living is roughly 88 (per BEA Regional Price Parities), so adjusted purchasing power on a $100,000 Caterpillar salary in Peoria runs roughly $113,600, materially better than a $120,000 salary in Chicago metro or a $135,000 salary in San Jose. For engineers optimising for spending power and a low-friction life around heavy machinery engineering, Peoria is one of the best deals in the country for the profession.

Chicago metro: corporate headquarters, pharma, and consulting

The Chicago metro mechanical engineering market is more diversified than any peer Midwestern metro. Boeing Chicago retains substantial engineering presence even after the 2022 HQ move to Arlington. Abbott Laboratories (Abbott Park) and AbbVie (North Chicago) employ several hundred MEs in medical device engineering, drug delivery system design, and manufacturing engineering. Baxter International in Deerfield adds to the medical and pharma engineering employment base. RR Donnelley (printing equipment), Komatsu Mining (mining equipment), McDonald's R&D (food equipment), and the Chicago consulting firms (Sargent and Lundy, CDM Smith Chicago, Burns and McDonnell) round out the metro base.

Pay bands in Chicago metro for MEs run roughly $63,000 to $77,000 entry, $90,000 to $115,000 mid-career, and $115,000 to $150,000 senior. Pharma and medical device employers (Abbott, AbbVie, Baxter) pay roughly 10 to 15 percent above the metro median across all bands, reflecting both the FDA-regulated complexity premium and the strong margin profile of the pharma sector. Pure consulting roles at Sargent and Lundy and the Burns and McDonnell Chicago office pay competitively at senior levels (often $120,000 to $145,000 base) and value PE licensure significantly.

Argonne, Fermilab, and the national lab ecosystem

Argonne National Laboratory in Lemont (operated for the Department of Energy by UChicago Argonne LLC) and Fermi National Accelerator Laboratory in Batavia (operated by Fermi Research Alliance) together employ several hundred mechanical engineers across particle accelerator engineering, detector mechanical systems, the Advanced Photon Source upgrade, nuclear engineering, and the Exascale Computing Project facilities engineering. Both labs hire across BS, MS, and PhD levels, with senior engineering bands typically requiring MS or PhD credentials.

Pay at the national labs is competitive with industry mid-bands but caps somewhat below private-sector aerospace and pharma equivalents. Entry-level MS hires typically start at $85,000 to $98,000 base, mid-career engineers reach $105,000 to $130,000, and senior engineers (often with PhDs) reach $130,000 to $165,000. The benefits package (TIAA-CREF retirement, generous leave, tuition support) is materially stronger than most private-sector equivalents, partially offsetting the senior band ceiling.

Industries that drive Illinois ME pay

Metro-by-metro pay

Career path for an Illinois ME

Entry-level offers in Illinois cluster in the $63,000 to $77,000 range, with the named-employer rotational programs (Caterpillar ECDP, Boeing internships converting to full-time, Abbott Engineering Development Program) running $72,000 to $90,000 base. By year five to seven, mid-career engineers at Caterpillar, Boeing Chicago, Abbott, or the major consulting firms reach $100,000 to $130,000 base. Senior bands (year ten plus) reach $130,000 to $170,000 at the premium employers, with pharma and medical device employers paying the higher end of that range.

PE licensure is materially valuable in Illinois's consulting and power-engineering sectors. The Illinois Department of Financial and Professional Regulation administers PE licensure under the Professional Engineering Practice Act of 1989. PE-licensed engineers at Sargent and Lundy (power), Burns and McDonnell, CDM Smith, and the Boeing-tied consulting firms typically earn $15,000 to $25,000 more than unlicensed peers at the same experience level. Industry-exempt employers (Caterpillar, Abbott, AbbVie, Argonne) generally do not require PE licensure.

Illinois imposes a flat 4.95 percent state income tax, in the middle of the US distribution. The COL index of 99 means take-home pay closely tracks nominal pay, with no major distortion in either direction. For an engineer choosing between Illinois and a no-income-tax state (Texas, Washington, Florida, Tennessee), the difference is roughly $4,500 to $7,000 per year on a $100,000 to $140,000 gross. That gap is typically more than offset by the industry diversity and depth of the Illinois market for engineers who value career flexibility over a few percentage points of take-home.

Frequently asked questions