He is portrayed by Malcolm-Jamal Warner. AJ Austin is the new star cardiothoracic surgeon at Chastain , but his incredible gifts come with a price. Keeping his overwhelming talent on line while controlling his moods is a constant balancing act. AJ is the new cardiothoracic surgeon at Chastain and Mina is tasked with showing him around, but she is caught off-guard by his volatile personality.
AJ performs a successful surgery on Micah Stevens ' aortic dissection, which was a complication of his heart transplant. During an operation with Mina, Austin gets high due to nitrogen narcosis and Mina used this time to get more information on the woman he was meeting with earlier. She learns that her mentor has been looking into his birth parents.
They are both prominent doctors, who chose their career over him a long time ago. His mother had gotten pregnant during med school and chose to give her son up for adoption. Austin seems okay with that truth, almost understanding the choice that was made. In After the Storm , he keeps in contact with Mina after she leaves back to Nigeria through texts. In Stuck as Foretold , Austin reveals he has been looking into finding his birth family. His mother had gotten pregnant during med school and chosen to give her son up for adoption.
His parents are currently married with two other grown-up children. AJ and Bell were not originally friends, upon his hiring, they disagreed on several occasions, Mina once told AJ that Bell might fire him on one occasion. In mid-season 2, after the death of Bradley Jenkins , which AJ was allegedly caused though it was actually caused by a defective heart valve made by QuoVadis , Bell stuck up for him, even telling them to write "Heart failure" as Bradley's cause of death on his death certificate, though it is unknown whether AJ knows about what was written.
Bell did occasionally show respect for AJ as a surgeon, on one occasion, he called him one of Chastain's best. In more recent seasons, Bell and AJ are shown to be closer and having somewhat of a friendship, with the two sometimes supporting each other with Bell even taking AJ out to the bar for drinks. Though rarely seen talking to each other in the early seasons, in later seasons, AJ and Conrad are shown to be somewhat friends, with Conrad even comforting AJ over his mother's death in Season 5.
