NAICS 541990 and PSC Y1BA contractors in Illinois

All Other Professional, Scientific, and Technical Services. CONSTRUCTION OF AIR TRAFFIC CONTROL TOWERS. Use this deeper state cross-code page to see which visible contractors sit in the overlap between these two lanes inside Illinois.

Illinois · NAICS 541990 · PSC Y1BA

Last updated: April 7, 2026

Visible recipients

Mapped obligations

$243,209,271

Buyer overlap

Top recipients

Visible recipients in the Illinois overlap of NAICS 541990 and PSC Y1BA

Walsh Federal LLC

Chicago, IL

Walsh Federal LLC is a federal category business profile based in Chicago, IL. The current public data layer shows $406,413,501 in visible federal obligations across 169 awards or transactions. Department of Defense appears as the strongest visible awarding agency. Top industry concentration is in NAICS 236220 (Commercial and Institutional Building Construction). The profile also shows meaningful product and service activity in PSC Y1BZ.

$243,209,271