US District Judge Tanya Chutkan, however, dismissed the states' claims against Trump himself, saying her court would not try to interfere with "the performance of his official duties" as US president.
The states' lawsuit could proceed against Musk and DOGE because it made a plausible claim that Musk's cost-cutting activities were "unauthorised by any law," according to Chutkan's ruling in Washington, D.C., federal court.
The attorneys general of New Mexico, Oregon and 12 other states filed their lawsuit in February, alleging that Trump has given Musk "unchecked legal authority" without authorisation from the US Congress.Â
The lawsuit seeks to halt DOGE's efforts to slash federal spending and shut down US agencies disfavoured by Trump.
"The court is right: the Constitution says Musk can't run the federal government unless the Senate confirms him," Oregon's attorney general, Dan Rayfield, said.
The White House and attorneys general for several other states that filed the lawsuit did not immediately respond to requests for comment.
Musk did not immediately respond to an email message seeking comment.
The states argued that Musk wields the kind of power that can be exercised only by an officer of the government who has been nominated by the president and confirmed by the Senate, and that DOGE itself has not been authorised by Congress.
DOGE has swept through federal agencies, slashing thousands of jobs and dismantling various programs, since Trump returned to office in January and put Musk in charge of rooting out what they say is wasteful spending as part of the president's dramatic overhaul of government.
Around 20 lawsuits have been filed in various federal courts challenging Musk's authority, which have led to mixed results.
