Billy Martin.

Who ever said lawyers were resistant to change?

William “Billy” Martin, the prominent Washington, D.C., trial lawyer, has swapped law firms every two years on average over the last 18 years. Earlier this month he landed at his ninth (and one of the largest) so far, leaving Miles & Stockbridge to become a partner in the white-collar and investigations group at Barnes & Thornburg.

“It's exciting,” Martin said on Wednesday. “After almost 45 years of practicing law, it's great to still be able to go into the office with a sense of excitement.”

Martin said he was attracted to Barnes & Thornburg by its larger platform and established practice, which includes a number of fellow former prosecutors.

In 2015, when he joined Miles & Stockbridge from a boutique he had founded two years earlier, Martin told The National Law Journal he billed between $3 and $5 million per year. He declined Wednesday to discuss how that figure had evolved since then, or how it might change at his new firm.

Aside from Miles & Stockbridge, Martin has charted a path through several other large firms, including stops at Manatt, Phelps & Phillips; Dyer Ellis & Joseph; Blank Rome; Sutherland Asbill & Brennan; Howrey; Dorsey & Whitney; and his own boutique, Martin & Gitner, all since 2000.

At Barnes & Thornburg, Martin is teaming up with former U.S. Attorneys Roscoe Howard and Mike Battle in D.C. He said his new office reminds him of his days working as an assistant U.S. attorney, and he likes being able to walk down the hall and call on colleagues that are leading lawyers in his practice.

Martin's high-profile clients and past representations have included the mother of Monica Lewinsky, the parents of Chandra Levy, members of the Washington Redskins, and defending former National Football League quarterback Michael Vick against dog fighting allegations. Given his experience as a celebrity trial lawyer, Martin said the opportunity to work with Barnes & Thornburg's entertainment and sports practice in Los Angeles was appealing too.

“It's been a long time since I've had this level of excitement,” Martin said.