With her placements at these three competitions, DiCello entered the August 2018 U.S. National Championships in Boston as one of the favorites for the Junior national title along with Wong, Bowers, and Sunisa Lee. After two days of competition in which she tallied an impressive score of 111.200, DiCello won the silver medal in the all-around competition, once again behind Wong. She performed well on both days of the competition and was the only junior gymnast to score in the top four on all four individual events: fourth on balance beam, third on uneven bars and floor exercise, and first on vault, where she stuck her double-twisting Yurchenko vault on the second day of competition to edge out Wong, the defending champion on the event. After her performance, she was once again named to the national team.