The current study investigated the impact of performance feedback on female students' motivation following a summative classroom assessment in STEM. Seventh through ninth grade students (N = 161) were randomly assigned by their math or science class to one of the following conditions: grades, written comments, grades and comments, and no feedback. Results revealed complex interactions between feedback stage (anticipation vs. receipt) and form. Students in the grades-and-comments condition experienced the most optimal effects (i.e., increased mastery goal orientation and intrinsic motivation) despite a decline in self-efficacy. Students in the comments condition experienced a similar increase in intrinsic motivation. Finally, students in the no feedback condition reported a heightened performance-approach goal orientation when they received assessments with no feedback. Theoretical, methodological, and practical implications are discussed.