Michael Bien billed about 2,800 hours last year — more than at any point in his career. More than half of it hasn’t been paid. And it may never be.

The managing partner at 17-lawyer Rosen, Bien & Galvan is lead counsel on the mental health part of California’s high-profile prison overcrowding litigation. He’s been working on Coleman v. Schwarzenegger for several years, but since the summer of 2007, the case has become the biggest at his San Francisco litigation firm. Media attention on the case hit a crescendo this summer, when a panel of three federal judges issued an unprecedented order telling the state to come up with a way to reduce the inmate population by 40,000 to bring prison conditions into compliance with constitutional standards. California’s appeal is taking the firm to the U.S. Supreme Court.