The White House did not respond to a request for comment about the departure of Pon, who was confirmed by the Senate in March.
But people close to Pon said he was at odds with the administration over its planned revamp of the personnel agency, which would have diminished his role and authority.
As part of a proposed government-wide reorganization announced by Trump in June, most of the OPM’s functions would be farmed out to other departments and its policy role shifted to the White House.
While Pon publicly backed the plan, he privately told lawmakers on Capitol Hill that the reorganization needed approval from Congress, a view that caused him to lose favor with the White House, according to a person with knowledge of the situation. Pon could not be reached for comment.
“He was in the position of trying to reform an organization the White House wants to abolish,” said Donald F. Kettl, a public affairs professor at the University of Texas at Austin.
Weichert will continue in her role as the OMB’s deputy director for management while serving as acting personnel chief — a move consistent with the administration’s efforts to bring decisions on federal personnel policies into the White House.
She has played a crucial role in creating a blueprint to shrink the role of the independent federal agency, which is responsible for employee background checks, retirement claims, benefits and workforce policy.
When asked whether her appointment is a step toward giving the White House more authority over federal workers, Weichert responded, “I wouldn’t say that it is directly related to that.”
“What I would say is that the broader objectives of the president’s management agenda are focusing on driving and really modernizing how we think about governing and our workforce in the 21st century,” she said in an interview.
In a statement, OMB Director Mick Mulvaney said, “Margaret has my full trust and support, and I know she will hit the ground running to ensure the federal workforce has the right skills and tools to deliver the proper services to the American people.”
Pon is a veteran human resources manager who has worked inside and outside government and served in a senior role at the OPM during the George W. Bush administration. He is widely respected as an expert on the federal civil service and how to reform it.
Pon, a political conservative, was not the White House’s first choice for the job, and his confirmation was prolonged for months.
While his appointment was pending, the White House did not inform him of its plans to shrink the agency’s footprint, according to three people with knowledge of the situation.
“He’s a very bright guy who’s exceptionally reasonable with respect to civil service issues, but I doubt he’s had the ability to push the agency in the direction he wants it to go,” said Jeffrey Neal, former personnel chief at the Department of Homeland Security and now a senior vice president at ICF, a consulting firm.
Pon’s departure will again leave the agency without a Senate-confirmed leader. Before Pon’s confirmation, the OPM had been led by acting directors since mid-2015, when then-director Katherine Archuleta was forced to resign after revealing the theft of personal information on more than 20 million people from two OPM databases.
The plan to shift personnel policy decisions into the White House has drawn opposition from federal unions that say that it would risk politicizing the hiring, promotion, disciplinary and other policies for career federal employees.
Pon had been focused on a different goal: pushing for a thorough overhaul of civil service laws on the 40th anniversary of the last major revision, the 1978 Civil Service Reform Act. He said that many of its provisions are now outdated.
Trump has issued three executive orders aimed at restricting the role of federal unions and enhancing management’s powers in disciplining employees. A federal court issued an injunction against major parts of all three orders, a decision that is being appealed.
Weichert said her appointment does not signal a change in the administration’s policies on the federal workforce.
“The direction that we’re going in, that has been spelled out in a number of documents including the reform and reorganization plan,” she said. “Those reflect the administration’s go-forward perspective. I think as we engage in the execution of some of those, we’re learning things that will inform the how of the execution. But I think the fundamental policy direction remains the same.”