Ryan makes his official debut in the new DC Rebirth continuity as a teenage genius Ivy League college student tutored by Ray Palmer. Palmer reveals his identity as the Atom and enlists Ryan's help in fighting crime, talking to Ray from his lab in a tech support role. One day, after many adventures together, Ray goes missing. A week later, Ryan finds a message from Palmer along with one of his size-changing belts, asking the youth to come find him in the Microverse because he got stuck there when exploring a change in time and space. After receiving another scolding from Dean Plumm, Ryan heads back to the lab, using the bio-belt that Ray gave him to travel there through the Wi-Fi. When he arrives, he is met by Batman and Lobo who are there to recruit Ray Palmer into the new Justice League of America. Discovering that Ray is missing, Batman decides to leave until Lobo asks Ryan if he wrote down various equations to update the bio-belt on a blackboard. Impressed, Lobo decides that Batman should recruit Ryan, despite Batman not wanting to put him in danger. Lobo says it is Ryan's choice, and Ryan joins the JLA and sometime later, heads to the City of Vanity, Oregon, to recruit the Ray into the team.