In the early 1990s, Lychnikoff moved to the United States. Since his subsequent move to Los Angeles, he has appeared in many TV movies and series and feature films. He is noted for his roles as the telegraph operator Blazanov in HBO's Deadwood series and as Russian mobster Vadim Youchenko in the movie Trade. He also appears as Howard Wolowitz's Russian cosmonaut crewmate Dimitri on the popular TV series The Big Bang Theory.