Phoenix has more large-scale development happening at once than most people realize. Each week I pick one worth watching and give you the real version, not the press release version. This week: the new West Terminal at Sky Harbor, the first new terminal at the airport since 1990.
American Airlines carried 20,893,285 passengers through Sky Harbor in 2025. That is 40.5% of everyone who used the airport, and the reason this terminal exists in the shape it does.
What was announced
The airport put out the details this week. The West Terminal will go on the west side of the airport, between Terminal 3 and a new Taxiway U. American is the primary carrier. The design is modular, so concourses can be added as passenger numbers grow, and the airport is planning for more wide-body aircraft and more international flights. Planning runs through 2026, design procurement is expected in 2027, construction could start in late 2029, and the target opening is late 2033. The airport itself says the timeline is subject to change.
Who pays
The airport's estimate is about $4.5 billion. That is not a final budget. The airport says the real number gets set during this year's planning work.
The money comes from passenger facility charges, bonds and airport funding. The airport says no tax dollars will be used.
A passenger facility charge is a fee built into your ticket price. Federal rules cap it at $4.50 per flight segment, and that cap has not changed since 2000. You have almost certainly paid it and never noticed. My own rough math: Sky Harbor handled 51.6 million passengers in 2025, so something like 25 million boardings. At $4.50 each, that tops out around $116 million a year, and not all of it goes to this project. That is an upper limit from my arithmetic, not an airport figure. The rest comes from bonds, which get paid back out of airport revenue over time.
Who moves
American leaves Terminal 4 for the new building. Southwest is the other big name here. In 2025 it carried 17.2 million passengers, 33.3% of the airport, so the two airlines together are about three quarters of Sky Harbor. Whatever American leaves behind in Terminal 4 is a large block of gates, and the airport has not said who gets them.
That is the part most coverage skips. Officially, airline assignments have not been determined, the terminal has no name or number yet, and the number of gates is open. The airport says the split between Terminal 3, Terminal 4 and the new terminal will depend on assignments and future air service. American being the primary carrier is announced. Everything after that is still open.
One more number
72% of Sky Harbor passengers in 2025 began or ended their trip in Phoenix, up from 60% in 2009. Fewer connecting passengers, more people actually going to or coming from the Valley. That is a big part of why the airport says Terminals 3 and 4 are fully built out and cannot add gates.
What happens to the rest of the airport
Terminal 4 is not being abandoned. The airport is also working on its baggage handling, concessions and building infrastructure. A separate six-gate concourse at Terminal 3 and Taxiway U are in the works too. On November 17 the airport is holding an industry day for contractors and small businesses on how the West Terminal will be built and bid out.
2033 is seven years away, and the final cost, gate count and airline map are all still unwritten. When the budget gets set, will $4.5 billion hold?
