Belconnen town centre has won the right to keep thousands of Immigration and Border Protection staff, but Canberra Airport is also a winner in the decision, announced on Thursday.
The decision to remain in Belconnen was expected, but the department also announced it would move about 1500 staff from Civic to the airport.
Staff at the airport will work at Brindabella Business Park on Molonglo Drive.
Belconnen workers will be spread out among 5-6 Chan Street and the ABS House, which is the north tower of 45 Benjamin Way.
The Australian Bureau of Statistics will move to the south tower of 45 Benjamin Way.
"Subject to successful lease negotiations and Public Works Committee approval, the fit-out of the new airport accommodation is anticipated to begin in July 2017, while the fit-out of the existing Belconnen facilities is anticipated to begin in 2018," the department said in a statement.
"All staff moves are expected to be completed by February 2021."
The department said it was considering current and future workforce needs.
ACT Liberal senator Zed Seselja, who has been fighting to keep the department's massive presence in Belconnen, said the decision was made possible because the federal government took local factors into account.
"Along with the Belconnen community I fought to ensure the [department] remained in its current location with the same staffing footprint, and I'm pleased that we won that fight," he said.
"Our government is the first ever to take into consideration local impacts on Canberra before making a decision regarding departmental accommodation, and today's announcement shows just how important this was.
"We now have certainty for businesses and staff located at the Belconnen town centre.
"We all know that the presence of government departments in our town centres is critical to maintaining the viability of many local small businesses. This is how Canberra was designed, and we need to protect that.
"A move of the DIBP from Belconnen town centre would not have been in the best interest of the Belconnen community. It was vital to ensure this did not happen.
"This is also welcome news for Canberra Airport, with staff anticipated to move to the new location from September 2018.
"Facilities and businesses around the airport will benefit from the increase in staff in the area."