Daniel Werfel, a longtime federal official who led the Internal Revenue Service after its targeting controversy and oversaw efforts to improve the government’s financial management, has quietly left public service.

Former acting IRS commissioner Daniel Werfel. (J. Scott Applewhite/AP).

The White House Office of Management and Budget, where Werfel served as controller from 2009 until assuming the role of acting IRS administrator in May, confirmed on Monday that Werfel’s last day with the government was Dec. 31.

Werfel said Monday that he plans to spend time with his family and explore new opportunities for the next phase of his career. “I have not yet decided on what my next steps will be, but hope to do so in the near term,” he said. “My tenure with both OMB and the IRS left me energized for new challenges.”

The IRS hinted last month that Werfel would leave public service after working through the end of the year to ensure a smooth transition for John Koskinen, a restructuring expert who was confirmed by the Senate last month to serve as IRS commissioner. Werfel said Monday that he saw Koskinen’s arrival as a good time to take a brief break and think about his future.

President Obama tapped Werfel to guide the IRS after the agency acknowledged using improper techniques to screen advocacy groups during the 2010 and 2012 election cycles. An inspector general’s audit found that the actions, which included focusing on certain groups because of their political ideology, largely affected conservative and tea party organizations.

Werfel led the IRS as the agency launched an internal investigation into the targeting scandal. The review found no evidence of intentional wrongdoing by IRS employees or proof that the White House directed the controversial efforts. Many Republicans questioned the findings.

As acting IRS administrator, Werfel was also responsible for implementing new safeguards to restore public trust in the agency and help it avoid future screening mistakes.

Overall, Werfel spent 16 years with the federal government, including 14 years with OMB, two as a career attorney with the Department of Justice, and seven months as interim head of the IRS.

During his tenure as OMB controller, Werfel was responsible for the government’s financial management, contracting, IT and personnel policies. He helped implement the White House’s “Campaign to Cut Waste,” oversaw a reduction of more than $2 billion in government travel costs, created plans to help trim the government’s real-estate portfolio and renegotiated several multi-million dollar IT contracts.

“The pace he’s been leading is quite extraordinary,” said Max Stier, president and CEO of the Partnership for Public Service, which has worked closely with Werfel in recent years.

Stier added that Werfel’s departure from government work after serving as an acting agency head is no surprise. “Once you’ve run a place, it’s hard to go back and play second fiddle,” he said. “You get used to a sphere of responsibility and control that’s hard to give up.”

Norman Dong has served as interim OMB controller since Werfel went to the IRS in May. Obama has not named a nominee to fill the role permanently.

Follow Josh Hicks on TwitterFacebook or Google+. Connect by e-mail at  josh.hicks@washpost.comVisit The Federal Eye, The Fed Page and Post Politics for more federal news. E-mail federalworker@washpost.com with news tips and other suggestion.