Notre Dame's first regular-season loss in two seasons has landed the program its lowest ranking in one year.
The Irish dropped to No. 21 Sunday in both polls. They entered the weekend at No. 14 in the Associated Press poll and at No. 13 in the USA Today Coaches' Poll.
Notre Dame's lowest previous ranking was also after Week 1 of last season, when it beat Navy to jump to No. 22 in both polls.
Michigan's 41-30 victory over the Irish allowed the Wolverines to jump from 17th in both polls to 11th and 12th in the AP and coaches' polls, respectively.