The Congressional Budget Office estimates it will cost taxpayers anywhere from $10 million to $125 million for Defense Secretary Pete Hegseth to rebrand the Defense Department as the "Department of War" -- a number that would grow to "hundreds of millions" if it became official.
The range is the first government cost estimate since President Donald Trump announced last fall that he wanted to "restore" the name of the Defense Department to the War Department.
Only Congress can change the name of a federal agency, so Trump last September signed an executive order calling for the new name to be used as a "secondary title," or essentially a nickname for the sprawling department.
"I think it sends a message of victory. I think it sends a message, really a message of strength. We're very strong," Trump said.
Hegseth embraced the new moniker on social media, referring to himself as the "secretary of war" and swapping out signs around the Pentagon in Arlington, Virginia.
According to the nonpartisan CBO, the cost is likely to be around $10 million if the name change is limited to within Hegseth's office.
Beyond that, any estimate would increase significantly depending upon how quickly -- and how broadly -- the name is changed.
For example, the cost would be lower if the Defense Department changes out stationery, signage and nameplates over time as needed, rather than swapping out those items all at once. Changing the name of a single Army base can cost some $5 million, according to the CBO.
The Defense Department's annual budget is close to $1 trillion.
"Costs would be at least a few million dollars if DoD phased in a minimal implementation, but they could be as large as $125 million if the name change was implemented broadly and rapidly throughout the department," the CBO wrote. "A statutory renaming could cost hundreds of millions of dollars depending on how Congress and DoD chose to implement the change."
The Pentagon did not immediately respond to a request for comment.