In January, it was announced that McCallum would represent the USA at the American Cup alongside first year senior Leanne Wong in March. There she won the silver all-around medal behind Wong and ahead of the two previous World silver all-around medalists, Ellie Black of Canada (2017) and Mai Murakami of Japan (2018), who tied for third place. At February’s team training camp, McCallum placed first in the all-around ahead of the other national team members.