He edited the films Cheerleader Camp, Think Big, 3 Ninjas Kick Back, and BASEketball.

He began directing television and film during the 1990s, his credits include Blood and Concrete, Mighty Morphin Power Rangers, The Sentinel, Trouble Bound, Haunted, Columbo, The Division, Surface, Friday Night Lights, Caprica and Trauma.

He was executive producer and house director for the NBC series The Event under his deal with Universal Media Studios during the show's 2010–2011 run.

[1] In 2011, Reiner was chosen to direct the pilot for a David E. Kelley-produced Wonder Woman television series for NBC.

Reiner has also worked on the FX TV series Fargo and in 2024, released the film Lake George, which he wrote and directed.