Plans to remake Washington Dulles International Airport expanded into a more than $20 billion project Wednesday as federal officials, the Metropolitan Washington Airports Authority and United Airlines unveiled an expanded redevelopment plan.

The proposal increases planned investment from about $7 billion, building on Dulles’ long-term master plan. Construction would take place in phases while the airport remains open.

The overhaul would replace the aging C and D concourses, expand the AeroTrain system, build a larger international arrivals and customs facility and add more than 5 million square feet of new and renovated space.

Plans also call for additional gates, upgraded baggage handling systems, expanded concessions and new passenger lounges while preserving architect Eero Saarinen’s iconic main terminal.

Airport officials said the project is designed to accommodate future passenger growth while modernizing infrastructure that has served travelers for decades.

“This new construction effort builds upon the multiyear Dulles Master Plan, developed in consultation with our airline partners, that will modernize Washington’s main international airport,” Airports Authority President and CEO Jack Potter said.

The Airports Authority said much of the project’s cost will be financed through municipal bonds issued in partnership with airlines serving Dulles. The announcement said the expanded project builds on improvements already planned while significantly increasing the airport’s long-term investment.

Virginia first-year Gov. Abigail Spanberger called Dulles one of Virginia’s most important gateways and said the expansion will create jobs, attract new business investment and strengthen infrastructure across the commonwealth.

Virginia Sens. Mark Warner and Tim Kaine, along with U.S. Rep. Suhas Subramanyam, also welcomed the announcement.

“These investments by United and MWAA will help Dulles service almost double the number of planes, passengers, and visitors,” Warner said.

Kaine said he looks forward to seeing the improvements modernize the airport, improve the customer experience, expand capacity and grow the region’s economy.

The expanded plan builds on improvements already underway at Dulles. Concourse E, a new 14-gate facility with direct access to the AeroTrain system, is expected to open later this year as the first major phase of the airport’s long-term redevelopment.

According to the Airports Authority, Dulles handled a record 29 million passengers in 2025, a 6.4% increase from the previous year.