DeBerg appeared in 13 games with 11 starts and passed for 2,935 yards with 16 touchdowns and 16 interceptions in his first season with the Chiefs, completing 224 of 414 passes. He defeated his old team (Denver) on September 18, 1988 in one of his better games of the year, throwing 259 yards and two touchdowns with no interceptions. DeBerg's best game was against the New York Jets on December 4, 1988, when he completed 16 of 25 passes for 267 yards and three touchdowns against one interception for a 38–34 win.