Stepheson said Friday in a statement that his family is facing unspecified health concerns.
Stepheson is a Los Angeles native who was the backup to Deon Thompson at power forward. In two years he averaged 3.16 points and 3.36 rebounds per game.
Coach Roy Williams said he is disappointed but understands Stepheson's decision because "by being closer to home, he will be able to provide the necessary support and help his family needs."
School officials said they have granted Stepheson's request for a release, a move that permits him to contact other programs.