Levin began his broadcasting career as a guest on conservative talk radio programs. For many years, he was a contributor of legal opinions to The Rush Limbaugh Show, appearing more regularly as the Monica Lewinsky scandal developed. About this time, Sean Hannity became aware of him, and he began to feature in Hannity’s radio show. Eventually, Levin gained a radio slot of his own on WABC, initially on Sundays beginning in 2002, then in the timeslot following Hannity’s program in 2003. Cumulus Media Networks began syndicating The Mark Levin Show nationally in 2006.
Levin has participated in Freedom Concerts, an annual benefit concert to aid families of fallen soldiers, and uses his radio program to promote aid to military families.[36] Levin is also involved with Move America Forward, a charity that sends care packages to soldiers serving overseas.
On February 11, 2016, Levin signed a ten-year contract extension with Westwood One, which will take his show through 2025, its 19th year.
On November 16, 2018, he was inducted into the National Radio Hall of Fame.