Ontario International Airport says its additional Terminal 4 security screening lane was completed on October 8, 2026, finishing a checkpoint expansion that also added capacity in Terminal 2. For Southern California travelers comparing airports for airline trips, this is a completed terminal improvement—not the opening of a new terminal.
According to the airport’s screening expansion project page, Terminal 2’s two additional lanes were completed on July 24, 2026. Terminal 4 received one additional lane; its exit corridor and restroom work had been completed earlier, on August 17, 2026. Both terminals received upgraded family restrooms and exit corridors.
The airport lists the project’s total cost at $11 million, including a $7 million Federal Aviation Administration grant. The completion dates are the airport’s account. The cited sources provide no independent measurements of wait times, so the added lanes should not be read as a promise of shorter security queues.
The larger redevelopment is a separate story. In its May 7, 2026, ONT BOLD release, the airport announced the start of an environmental impact report process. That proposal includes a new Terminal 3, modernization of existing Terminals 2 and 4, and work involving roads, parking and aircraft apron areas. The announcement marked the beginning of environmental review, not a final decision to build. It does not establish that construction funding was secured or that work on Terminal 3 had started.
The state’s CEQAnet record, SCH 2026050357, lists a Notice of Preparation received on May 8, 2026, with the Ontario International Airport Authority as lead agency. It records the proposed Terminal 3 and modernization plans. This is a planning record, not confirmation of the checkpoint completion, and it does not establish the proposal’s current approval status.
The useful distinction for airline passengers is scale and timing: the airport reports the screening upgrades complete, while the May Terminal 3 documents describe a much broader proposal entering review.
