This short-term longitudinal study explored the unique role of proximal classroom factors (teachers' student-specific self-efficacy, autonomy-supportive behaviors, and student-teacher relationships) in students' emotional and behavioral engagement, and the moderating role of grade level. Participants were 472 students and 63 teachers (grades 4-6). Path models examined within-time and longitudinal associations between proximal classroom factors and engagement, and multigroup models explored the moderating role of grade level. Results indicated significant within-time associations among all proximal classroom factors and students' engagement. When initial levels of engagement were controlled for, teachers' student-specific self-efficacy predicted positive changes in emotional engagement, and closeness predicted positive changes in behavioral and emotional engagement. The association of closeness with the engagement measures was strongest for students in 6th grade.