Hellas Verona sealed an immediate return to Serie A with a draw on the final day of the Serie B season on Thursday.
Verona's goalless draw at Cesena was enough to see them finish second above Frosinone thanks to the head-to-head tiebreaker.
Frosinone beat Pro Vercelli 2-1 but will settle for the playoffs alongside Benevento, Spezia, Cittadella, Carpi and Perugia.
Frosinone would have avoided the playoffs if they had ended the regular season 10 points clear of fourth place. However, Perugia and Benevento also won to leave the gap at nine points.
SPAL, which sealed promotion last week after 49 years out of the top flight, won the Serie B title with a 2-1 win over Bari.