[2] His mother is Marcia Muir Mitchell, a writer,[3][4][5][6] and his father is Robert "Bob" Feldman, who runs a Maryland advertising agency.

He attended Winston Churchill High School in Potomac, Maryland and graduated with the class of 1998.

[16] In 2024, Feldman was nominated for a Logie Award for his work on the Stan Australia series Population 11.

[18] In April 2012, he joined the cast of AMC's Mad Men as a regular, playing the character Michael Ginsberg.

[19] He also appeared as lawyer Ron LaFlamme on HBO's Silicon Valley[20] from 2014 to 2019, and from 2015 to 2021 played the lead Jonah Simms in the NBC sitcom Superstore.