Wells' first request for eligibility had been denied previously by the NCAA.
"We're excited for Dez, because at the end of the day, the NCAA made the right decision," said basketball coach Mark Turgeon, according to the university's website. "Our staff did an incredible job in putting this NCAA waiver appeal together on Dez's behalf. Dez has been a welcomed addition, a great teammate, and has made a seamless transition in getting acclimated to our campus.
"This has been a long process for him and his family, and we're grateful he can put it behind him and focus on being a student-athlete at the University of Maryland."
An All-Atlantic 10 rookie selection last season, the 6-foot-5 Wells was expelled from Xavier as a result of sexual assault charges that were rejected earlier this year by a grand jury.
Before his dismissal, Wells was Xavier's top returning scorer at 9.8 points and 4.9 rebounds a game. He started 32 games as a freshman for the Musketeers.
ESPN.com's Dave Telep contributed to this report.