Einhorn is best known for his work as a cinematographer and occasional director on The Office. He also directed The Accountants, a ten-part webisode spin-off of The Office which appeared online between the second and third seasons. In tribute to Einhorn's contribution to the series, the Season 6 episode of The Office, The Cover-Up, was dedicated to Larry Einhorn, Randall's father, who died on April 20, 2010. Randall also plays the role of CFO of Dunder Mifflin, until he resigns in Season 2, Episode 2 of "The Office"
Between 2009 and 2011, while still working on The Office, Einhorn took on the roles of producer and director for 14 episodes of It's Always Sunny in Philadelphia. He went on to direct several episodes of Parks and Recreation and Fargo and produce and direct for Nurse Jackie and all but three episodes of Wilfred.
Since working on The Muppets, Einhorn has continued to produce and direct for various comic film and television projects, including The Mick[5] and The Kids Are Alright. Recently, he and his Sad Unicorn production company made a multi-year, first-look deal with Warner Bros. Television.[6]
In 2019, he has sold two single-camera comedy projects for fall 2020 consideration, Us & Them to NBC and Married with Roommates to ABC.[7]