A massive Southeast D.C. building that houses over 5,000 public sector employees could soon come under federal government ownership.

The General Services Administration announced Friday it exercised its option to acquire the Department of Transportation headquarters at 1200 New Jersey Ave. SE for $760M.

The agency expects the sale to close in March. The GSA said buying the building rather than leasing it will save the government $409M over the long-term, and acquiring the property early ahead of its lease termination is saving it about $100M.

President Donald Trump's administration included $768M to buy the building in its Fiscal Year 2019 budget. The GSA said it is the final Cabinet-level agency to move its headquarters from leased to owned space.

"We are proud to have successfully used the money appropriated from our partners in Congress for this project and to deliver on the mission of providing effective workplace solutions for federal agencies at the best value for the American taxpayer," GSA Public Buildings Service Commissioner Dan Mathews said in a statement.

The JBG Cos., before it merged with Vornado/Charles E. Smith and became JBG Smith, developed the 1.5M SF office building in 2006. It is still owned by the entity JBG/Federal Center LLC, a separate fund from JBG Smith, but it is managed by the REIT. Sitting one block east of the Navy Yard Metro station, the 5,500-person headquarters facility helped spark a period of significant growth for the Capitol Riverfront neighborhood.