Chicago O'Hare's $12 Billion Modernization Stretches to 2034
The airport's massive O'Hare 21 program has ballooned from an $8.5 billion, eight-year plan into a $12 billion effort that will now take sixteen years to complete.
Chicago O'Hare International Airport is proceeding with a comprehensive terminal overhaul that has grown substantially in both cost and timeline since its 2018 approval, with the modernization program now expected to run through 2034.
The O'Hare 21 initiative, originally budgeted at $8.5 billion for completion within eight years, has expanded to roughly $12 billion in current dollars and will require sixteen years to finish, according to a report. The expansion addresses infrastructure constraints at a facility serving more than 80 million travelers yearly through terminals that have gone without significant capital investment for over a quarter-century.
Central to the program is a new 2.2 million square foot Global Terminal designed by Chicago architect Jeanne Gang, alongside two satellite concourses and an underground tunnel network connecting passenger facilities. The modernization also encompasses updates to existing terminals, some of which date to the early 1960s and were built before contemporary security protocols and widebody aircraft gate requirements became standard.
Work on the Terminal 5 expansion, the first completed segment of the broader effort, wrapped up in 2023 and delivered ten additional widebody gates while increasing international capacity by one-quarter. Vertical construction on Satellite Concourse 1 commenced in April 2026, with the Global Terminal slated to follow in the construction sequence.
The infrastructure being replaced reflects decades of incremental development across different architectural eras. Terminal 1 underwent a comprehensive redesign by architect Helmut Jahn that concluded in 1987 as United Airlines' primary facility, while Terminal 3 has received periodic updates without a full reconstruction. Terminal 5, the airport's international gateway, opened in 1993.
The modernization program also incorporated completion of Runway 9C-27C in 2020, finishing a separate $6 billion, sixteen-year airfield reconfiguration that replaced the airport's previous runway layout.