The Defense Department’s Chief Financial Officer and Comptroller David Norquist has assumed the role of acting deputy defense secretary as Patrick Shanahan took over as Pentagon civilian chief on Jan. 1, the department said Jan. 2.

“As Department of Defense Chief Financial Officer and Comptroller for the past 19 months, David Norquist has had insight into virtually every tenet of this department,” Shanahan said in a statement Wednesday. “I have the greatest confidence in his abilities to lead a phenomenally talented team while performing the duties as Deputy Secretary of Defense.”

DOD Comptroller and Chief Financial Officer David Norquist. (Sgt. Amber I. Smith/U.S. Defense Department)

Shanahan, who was sworn in as deputy secretary of defense in July 2017 following three decades as a Boeing [BA] executive, was named acting secretary of defense after President Trump announced in late December that James Mattis would be leaving the department effective Jan. 1. Mattis, a retired Marine Corps general and former U.S. Central Command commander, announced his resignation Dec. 20, but planned to stay on as defense secretary until Feb. 28.

Norquist, who led the Pentagon’s first-ever audit process over the past year, is sure to play an integral role in the Pentagon’s fiscal year 2020 budget deliberations over the next month. The department plans to release its annual presidential budget request Feb. 8, but it currently remains in “pre-decisional budget coordination,” a Pentagon spokesperson said Wednesday.

Acting officials have a 210-day limit, per the Federal Vacancies Reform Act of 1998. It is unclear whether President Trump plans to nominate Shanahan to officially become the next defense secretary, or who else he may tap for the job.

During his tenure at Boeing, Shanahan most recently served as senior vice president for supply chains and operations. He previously served as vice president and general manager for Boeing Missile Defense Systems, as well as for the company’s rotorcraft systems and commercial airplanes divisions.

As deputy defense secretary, Shanahan recused himself from participating in any DoD matters involving Boeing for the first two years of his post. On Wednesday, his spokesman Army Lt. Col. Joe Buccino said in a statement that Shanahan has recused himself from such discussions “for the duration of his service in the Department of Defense.”