Although now a senior national champion, Nagasu did not meet the International Skating Union's age criteria to compete at the World Championships. Of the four top finishers at the 2008 U.S. Championships, only Ashley Wagner was old enough to compete at senior Worlds, with the other medalists sent to Junior Worlds in Sofia. In Bulgaria, Nagasu outscored Zhang by 2.47 points in the short program. She placed third in the free skate, 14.21 points behind Flatt and 11.42 points behind Zhang. For the second year in a row, Nagasu was part of an American sweep of the podium, winning the bronze medal 8.95 points behind silver medalist Zhang, and 9.30 behind Flatt, who took the gold.