His practice focuses on personal injury, civil rights litigation and medical malpractice cases.

Fieger served as the defense attorney for Jack Kevorkian and was an unsuccessful Democratic nominee for governor of Michigan in 1998.

On March 1, 2024 Fieger's wife released a statement saying he was diagnosed with a heart condition that required surgery, and afterward he suffered a stroke.

These events were made into a movie, You Don't Know Jack, aired on HBO, in which Fieger was portrayed by actor Danny Huston.

Other notable clients and cases include: In 1998, Fieger ran unsuccessfully as the Democratic nominee for Governor of Michigan.