After leaving NBC, Stern moved into the morning drive time slot on WXRK-FM, also known as K-ROCK. In 1986, Infinity Broadcasting, now CBS (CBS) Radio, started airing Stern's show nationwide. It soon claimed the top spot in Philadelphia, Los Angeles and several other major markets.
In 1992, Stern received his first of many fines from the Federal Communications Commission. Infinity Broadcasting had to pay $600,000 after Stern talked about masturbating to a picture of Aunt Jemima on air. By 2005, Stern had racked up around $2.5 million in fines from the FCC for his employers.