Atkinson is known for alerting Congress in September 2019 to a whistleblower complaint about President Donald Trump pressuring Ukraine to investigate political rival for the presidency Democrat Joe Biden and his son Hunter Biden; the scandal eventually led to Trump's impeachment and acquittal.

[7] He was nominated to the position in November 2017 by President Donald Trump[13] and was confirmed by the United States Senate by voice vote on May 14, 2018.

[14] At his confirmation hearings, Atkinson indicated that he would bring order to the troubled ICIG's office, which had a reputation for dysfunction, and pledged to revive a whistleblower program that had become virtually defunct under the previous Acting Inspector General,[15] saying that he would "encourage, operate, and enforce a program for authorized disclosures by whistleblowers within the intelligence community that validates moral courage without compromising national security and without retaliation.

[15] In August 2019, Atkinson, as inspector general, received a formal complaint from a whistleblower within the Executive Office of the President of the United States who stated that they had learned, in the course of normal duties, that Trump had abused his power "to solicit interference from a foreign country in the 2020 U.S. election," specifically by pressuring a foreign government (Ukraine) to investigate former Vice President Joe Biden and his son Hunter Biden.

[20] Under ICWPA, the DNI "shall" forward a complaint deemed credible and of urgent concern, within seven days of receipt, to the Senate and House Intelligence Committees.

[24] In a letter to the House Intelligence Committee, Atkinson said that he and Maguire were "at an impasse"[11] and wrote that "As it now stands, my unresolved differences with the Acting DNI are affecting the execution of two of my most important duties and responsibilities" (to whistleblowers and to Congress).