The head of the beleaguered U.S. Postal Service, Louis DeJoy, resigned Monday after nearly five years in the position, leaving as President Donald Trump and Elon Musk’s Department of Government Efficiency have floated the idea of privatizing mail service.

DeJoy had said last month he planned to step down but hadn’t set a date. He leaves an agency with an uncertain future. Trump has said he is considering putting USPS under the control of the Commerce Department in an attempt to stop losses at the $78 billion-a-year agency, which has struggled at times to balance the books with the decline of first-class mail.

Deputy Postmaster General Doug Tulino will take on the role until the Postal Service Board of Governors names a permanent replacement for DeJoy, who became postmaster general in the summer of 2020 during Trump’s first term. He was a Republican donor who owned a logistics business and was the first person to hold the position in nearly two decades who was not a career postal employee.

“I believe strongly that the organization is well positioned and capable of carrying forward and fully implementing the many strategies and initiatives that comprise our transformation and modernization, and I have been working closely with the Deputy Postmaster General to prepare for this transition, DeJoy said in a statement.

The National Association of Letter Carriers’ president, Brian L. Renfroe, said in a statement Monday that the union stands ready to work with whomever the board selects as the next postmaster general.

“The future of the Postal Service is on the line, and choosing someone with innovative ideas and appreciation for our Constitutionally mandated service is essential,” Renfroe said.

Earlier this month, DeJoy said he planned to cut 10,000 workers and billions of dollars from the USPS budget and he’d do that working with DOGE, according to a letter sent to members of Congress.