In a statement released Friday, Hairston said he submitted the paperwork Friday afternoon.
"I've spent the past couple of weeks consulting with my family about what's best for me, my development and my future," Hairston said.
Hairston also said he is enrolled in an online course at UNC.
"[I am] taking a class in my major that will be applied towards getting my communications degree. I turned in my first assignment yesterday," he said. "I am excited to continue to pursue my degree at UNC while also pursing my dream of becoming a professional basketball player."
Hairston is not eligible to play in the NBA this season, but must instead enter the 2014 draft process.
Hairston confirmed on Instagram this week that he is in Chicago. The post came just hours after Hairston tweeted "My dream stands in front of me" and "Next stop, Chi Town!".
It was less than a month ago, UNC announced Hairston would not return to the Tar Heels. The university decided it would not apply to the NCAA to reinstate Hairston. "Unfortunately P.J. made a number of mistakes that placed his eligibility at risk and the University's joint review with the NCAA made it clear that seeking reinstatement for P.J. would not be possible," said director of athletics Bubba Cunningham. "The University thanks him for his contributions to Carolina Basketball.
UNC head coach Roy Williams suspended Hairston indefinitely after a summer drug arrest and after he received multiple speeding tickets.
"P.J. made mistakes and I was very disappointed by his actions and now he is suffering the very difficult consequences. He is not a bad kid; he just made some mistakes," said head coach Roy Williams.
Hairston and his family released a statement, shortly after UNC made its decision public, expressing their disappointment in the program.
"We are displeased with the University of North Carolina's decision not to submit the necessary paperwork to the NCAA requesting to have P.J. reinstated. This process has been long, and for it to end without having a final decision from the governing body is a shame. Ultimately this affects P.J. and his eligibility to play Division 1 collegiate basketball for the remainder of this season, as well as next season.
Despite our disappointment, we wish the team continued success.
UNC said Hairston scored 707 points and made 127 three-pointers in 71 games as a Tar Heel. Last year, he led UNC in scoring at 14.6 points per game and connected on 89 threes, the second-most in Carolina single-season history.