How an arcane Treasury Department office is now ground zero in the war over federal spending

A few weeks before Donald Trump was sworn in as president, members of his transition team went to the Treasury Department to talk about the handover of power.

A few weeks before Donald Trump was sworn in as president, members of his transition team went to the Treasury Department to talk about the handover of power. But what is normally a routine discussion turned into an alarming series of interactions for a handful of top career Treasury officials. Trump’s team, which included members of Elon Musk’s Department of Government Efficiency peppered Treasury officials about one of the department’s most sensitive and critical functions: processing trillions of dollars in government payments a year. Through a series of specific requests, Trump’s landing team attempted to lift the hood on the department’s Bureau of the Fiscal Service, an arcane branch that distributes nearly 90 percent of all federal payments, including Social Security benefits, tax refunds and payments to federal workers and contractors. That adds up to a billion annual transactions totaling more than $5 trillion. A month later, this obscure Treasury office is now a key battlefront in a wider war being waged by Trump and his allies over federal spending. Signs of the fight have emerged this week. The top civil servant at the Treasury Department, David Lebryk, is leaving unexpectedly after Trump-affiliated officials expressed interest in stopping certain payments made by the federal government, according to three people familiar with the situation.