Mendel first worked in television as a production assistant on All My Children and Loving during his summer breaks from studies at Syracuse University.

For his work on The Simpsons, Mendel won three Primetime Emmy Awards for Outstanding Animated Program in 1995 ("Lisa's Wedding"), 1997 ("Homer's Phobia"), and 1998 ("Trash of the Titans").

[3][4][5][6] After departing The Simpsons, Mendel produced shows such as The PJs, The Oblongs, Drawn Together, Sit Down, Shut Up, and Napoleon Dynamite.

[5] A resident of Studio City, Los Angeles, he was married to Juel Bestrop, a casting director for the series Brooklyn Nine-Nine and Life in Pieces, and had two children.

[6] Mendel died at his home in Los Angeles on September 22, 2019, from natural causes, two days before his 55th birthday.