Werfel was previously the controller of the White House's Office of Management and Budget.
In his first month on the job, Werfel has been tasked with reviewing the matter to find out who was responsible and hold them accountable, as well as identify any systemic issues at the IRS that could have allowed the targeting to occur, according to Lew.
Lew appeared before the panel to discuss the latest state of financial regulation, but the IRS scandal loomed large over the topic of the day.
Chairman Tim JohnsonTim JohnsonCourt ruling could be game changer for Dems in Nevada Bank lobbyists counting down to Shelby’s exit Former GOP senator endorses Clinton after Orlando shooting MORE (D-S.D.) opened the hearing to express his "sincere disappointment and anger" over the practice, and commended the Obama administration for taking "swift action." Sen. Mike CrapoMike CrapoA guide to the committees: Senate Time for the feds to deregulate gun suppressors Senate votes to repeal transparency rule for oil companies MORE (R-Idaho), the ranking Republican on the panel, said he would be "remiss" if he did not address the IRS matter even though the committee does not technically have jurisdiction over the "troubling and disturbing" matter.