Cameron Rodriguez, a 23-year-old sophomore forward for Winfield, Kan.-based Southwestern College, sank the promotional shot on Nov. 8 during the Thunder's home game against the Denver Nuggets.
Southwestern athletic director Dave Denly says the college's governing body for athletics, the National Association of Intercollegiate Athletics, informed Rodriguez that if he kept the money he would lose his amateur status. The school has appealed, asking if the money can be accepted in the form of a scholarship.
NAIA spokesman Chad Waller confirmed the organization is looking into the matter and said a ruling could take two weeks.
Eight lucky fans have hit the half-court shot, sponsored by a local bank, in 231 home games since the promotion started, said Thunder spokesman Dan Mahoney.
"We've been in communication with Cameron," Mahoney said. "He's a great kid, and we hope it works out best for him."
For his part, Rodriguez, of Elk City, Okla., said he never considered taking the money and forfeiting his college athletic career.
"In my eyes, it's just money," said Rodriguez, who receives a partial scholarship that offsets some of the cost of his tuition. "I know I'm a college kid who can use some help, but my love for basketball and my passion for the sport—it's worth more to me than $20,000."
If he's unable to accept the money in the form of a scholarship, Rodriguez said he hopes the proceeds can be donated to a charity or nonprofit.