Kevin McCarthy’s Former Chief Counsel Joins Mayer Brown

Kimberly Hamm, once chief counsel to former US Securities and Exchange Commission chairman Jay Clayton and US Speaker of the House of Representatives Kevin McCarthy, is heading to Mayer Brown in Washington DC.

Hamm, who also previously spent four years in the House’s general counsel office, is joining Mayer Brown as leader of its congressional investigations group, the firm announced Wednesday.

“The firm is really known for complex, difficult, multi-front investigations,” Hamm said in an interview with Bloomberg Law.

As she was looking for her next step, Mayer Brown was a “natural fit” because of that investigations piece, but also its focus in financial services, she said.

Kimberly Hamm

“It was really important to me to be able to merge investigations with that financial services or regulatory policy work,” she said.
Hamm has spent nearly two decades working on complex litigation, investigations and regulatory policy in top roles in Congress, the SEC and in Big Law.

After more than a decade at Simpson Thacher & Bartlett, Hamm joined the House of Representatives’ Office of General Counsel in 2014, where she advised committees on all aspects of congressional investigations and represented House members and committees in numerous grand jury, trial, and appellate proceedings on a wide range of issues.

Hamm joined the SEC in April 2019 and was named chief counsel to chair Jay Clayton in August 2019, where she oversaw regulatory initiatives across all divisions of the SEC, including the issuance of more than 45 final rules.

She joined Kevin McCarthy’s office in April 2023 as deputy general counsel and was promoted to general counsel the following month. As chief counsel to Speaker McCarthy, she provided strategic guidance to House committees on congressional investigations and oversight, including issuance and enforcement of committee subpoenas to agencies and private parties.

Hamm stayed in the Speaker’s office until December 2023, assisting with the transition after McCarthy was removed from office through a historic motion to vacate.

“There are very few people in town who have Kim’s unique background,” said Mayer Brown partner and former senior White House economic advisor Andrew Olmem.

Hamm has “a really unique perspective and ability to counsel clients on the most complex investigative and regulatory matters that they may be facing,” he said in an interview with Bloomberg Law.

Hamm joins a growing roster of former top senior goverment officials in Mayer Brown’s Washington office that includes former U.S. Deputy Secretary of State and Ambassador John Sullivan, Senator Amy Klobuchar’s former chief of staff Jonathan Becker, and former Department of Justice official Adam Hickey.