He graduated magna cum laude with a BA in physics from Duke University in 1961, where he was a member of the Sigma Chi fraternity and Phi Beta Kappa.

[citation needed] Prior to entering government service, Koskinen worked for 21 years for The Palmieri Company as vice president, president, CEO, and chairman, working on the turnaround of large, failed enterprises such as the Penn Central Transportation Company, Levitt and Sons, the Teamsters Pension Fund, Mutual Benefit, and Equity Programs Investment Corporation.

Earlier in his career, Koskinen clerked for Judge David L. Bazelon, chief judge of the U.S. Court of Appeals for the District of Columbia, from 1965 to 1966, practiced law with the firm of Gibson, Dunn and Crutcher from 1966 to 1967,[5] and served as the special assistant to the deputy executive director of the National Advisory Commission on Civil Disorders (the "Kerner Commission") from 1967 to 1968.

The hearings also focused on the length of time it was taking the IRS to respond to requests for documents and the circumstances surrounding the hard drive crash in 2011 of the computer of Lois Lerner, a major figure in the overall investigation.

On November 24, 2015, Koskinen signed a memorandum that commits the IRS to fostering a model workplace free of conduct that negatively impacts employee engagement and productivity.

[11][12] Those sponsoring the impeachment resolution to remove Koskinen from office accused him of failing to prevent the destruction of evidence in allowing the erasure of backup tapes containing thousands of e-mails written by Lerner, and of making false statements under oath to Congress.

[11][12] In a statement released by the committee, Chaffetz said Koskinen "failed to comply with a congressionally issued subpoena, documents were destroyed on his watch, and the public was consistently misled.

[12] Representative Elijah Cummings (D-Maryland), the committee's top Democrat, said in a statement: "This ridiculous resolution will demonstrate nothing but the Republican obsession with diving into investigative rabbit holes that waste tens of millions of taxpayer dollars while having absolutely no positive impact on a single American.