WASHINGTON — More than a dozen Democratic senators sent a letter to Heather M. Hill, the Treasury Department’s acting inspector general for tax administration, requesting an investigation into the departure of Kenneth Kies. The senators sought a review of the circumstances surrounding Kies's exit from his government roles.

Kies left his roles as assistant Treasury Department secretary and acting chief counsel of the IRS earlier in July 2026. The White House confirmed Kies's departure in an email statement. In that statement, the White House said Kies was not a team player and was difficult to work with.

It was reported that Kies warned political officials risked breaching a law barring executive branch interference in tax enforcement. Kies was confirmed to lead the Office of Tax Policy in June 2025, a position he held before his recent exit. The Treasury Department's Office of Tax Policy is responsible for developing federal tax policy and overseeing the implementation of tax legislation.

Kies previously served as chief of staff for the Joint Committee on Taxation. His professional history also includes a period where he recused himself from tax matters involving Donald Trump due to his prior work as Trump’s private lawyer.