The present study used the Early Childhood Longitudinal Study, Kindergarten Class of 2011 (ECLS-K:2011) to examine the bidirectionality and co-occurrence between math achievement and behavioral outcomes of upper elementary school students. We analyzed the cross-lagged relations across four groups of students who had different initiating statuses in math achievement and behaviors. We found a negative feedback cycle initiated by early learning difficulties in math, where math achievement significantly predicted behavioral outcomes, which subsequently predicted math achievement in later grades in all risk groups. The opposite direction of the path was not considered significant (i.e., behavioral difficulties did not initiate a negative feedback cycle). We also found that behaviors in grade 4 mediated the relationship between math achievement in grades 3 and 5. Findings indicate that cross effects of early math achievement may lead to positive outcomes in both math achievement and behaviors in later grades. The implications and limitations are discussed.