Elon Musk’s Department of Government Efficiency is now seeking to investigate a federal agency with a mission similar to its own: the Government Accountability Office, which has been hunting for waste and inefficiency in government since the 1920s.
The Government Accountability Office said in a statement on Friday that it had rejected a request from Mr. Musk’s group to “assign a team” to the century-old budget agency.
“As a legislative branch agency, G.A.O. is not subject to executive orders and has therefore declined any requests to have a DOGE team assigned,” the agency said in its statement.
A spokeswoman for the Government Accountability Office declined to say when the agency was first contacted by Mr. Musk’s group. A spokesman for Mr. Musk’s group did not immediately reply to a request for comment. The confrontation between the two watchdog groups was first reported by Wired.
Mr. Musk’s group has audited agencies across government, and claims to have found $170 billion in savings, although that figure is inflated by errors, guesswork and zombie contracts that were killed but later reinstated.
On the surface, the Government Accountability Office would seem less like a target and more like an ally of Mr. Musk’s group. The office audits federal programs for waste, fraud and mismanagement. Its budget is about $900 million, but the agency says it saves $76 for every dollar invested in its work.
But now the accountability office could become a roadblock for President Trump, who set Mr. Musk’s group in motion.
The older watchdog agency, led by Comptroller General Gene L. Dodaro, finds itself at the center of a brewing battle over a power known as impoundment, the ability of the president to halt the delivery of funds that have been appropriated by Congress.
In his sweeping reconfiguration of American government, Mr. Trump has claimed he has vast powers to direct the course of the nation’s spending. He and his leading budget adviser, Russell T. Vought, maintain that a 1970s law restricting impoundment is unconstitutional, setting up a potential legal clash around the power over the nation’s purse.
Still, the statute empowers the Government Accountability Office to investigate potential violations, and in late April, Mr. Dodaro acknowledged his team had opened more than three dozen probes into reports that the Trump administration illegally withheld congressionally authorized funds.
“We’re trying to get information from the agencies about what their legal position is for not expending the money,” Mr. Dodaro told the Senate at a hearing, as he acknowledged some agencies had been “unresponsive” to the inquiries.
Mr. Dodaro did not signal how his office might proceed, but it has the power under law to sue the administration for violations.
A similar showdown arose at the end of Mr. Trump’s first term, as Democrats moved to impeach him. The Government Accountability Office found that the administration had violated the law by illegally withholding roughly $400 million in aid to Ukraine in defiance of Congress, though the administration claimed it had acted lawfully.
Senator Patty Murray of Washington, the top Democrat on the Senate Appropriations Committee, said in a statement that Mr. Musk’s group has no power over the older watchdog group.
“The law is crystal clear: G.A.O. is a legislative branch agency not subject to DOGE or the president’s whims,” Ms. Murray said in a statement. “It is an indispensable, impartial government watchdog, and its independence must remain. My message to Elon and DOGE: get lost.”
Mr. Trump has already faced pushback from legislators of both parties over his effort to take over another congressional institution: the Library of Congress. Mr. Trump recently fired the librarian of Congress before the end of her term, and sought to replace her with his former personal lawyer, now a top official at the Department of Justice.
