Executive functions (EFs) are linked to children’s overall math performance, although few studies have considered the joint role of prior math abilities for specific math subskills, such as arithmetic. The current study examined the longitudinal contributions of preschool EFs and early math abilities to children’s accuracy and reaction time on arithmetic problems. Two hundred and eighty-three children completed EF and numeracy assessments at 5.25 years old. Children completed an arithmetic problem task in first (Mage = 7.14), second (Mage = 8.09), and third grade (Mage = 9.08). Results indicated that preschool EFs and math abilities are uniquely linked to children’s accuracy and reaction time at age 7, whereas preschool EFs alone continue to predict accuracy at age 8 and reaction time at age 9, even after accounting for intervening arithmetic performance. The study highlights the sustained, unique importance of early EFs for children’s arithmetic acquisition. (author abstract)