Sen. Orrin Hatch (R-Utah) is losing his longtime tax policy adviser Evan Liddiard, who is joining the boutique lobby shop Urban Swirski & Associates as a partner.

Liddiard spent 20 years on Hatch’s staff, and in addition to tax matters, he also advised the Senator on federal budget, financial services and Social Security issues.

“Evan has been a tremendous asset to me and the people of Utah for the past two decades,” Hatch, the top Republican on the Finance panel, said in a statement released by the lobby firm. “He will be greatly missed by the Finance Committee and by his colleagues and me.”

“As tax reform gears up, Evan’s deep understanding of the legislative process coupled with technical tax proficiency will be a huge added value to our clients,” said the firm’s Anne Urban, a Democrat who previously worked on the Hill for then-Sen. Bob Kerrey (D-Neb.).

Liddiard will also join the financial and investment advisory firm Dominion Financial Consultants and will teach a tax policy graduate course at American University.