This study assesses the impact of a 2-year virtual coaching program on teacher and student outcomes. The program - Feedback on Alignment and Support for Teachers (FAST) - was intended to deepen teachers' understanding of their state's standards and improve the alignment of their instruction with the standards. Relying on a multisite school-level randomized controlled trial, we assessed the impact of the FAST program in fourth-grade math and fifth-grade English language arts (ELA). We found that the program had a positive impact on the alignment of teachers' instruction with state standards for both math and ELA teachers (effect sizes = 0.70 and 0.40, respectively), although the impact was statistically significant only for math teachers. In contrast to a growing body of evidence on the benefits of instructional coaching, the program's impact on student achievement, was in the negative direction for both fourth-grade mathematics and fifth-grade ELA (effect sizes = -0.07 and -0.10, respectively), although the impact on achievement was statistically significant only for ELA. These results suggest that improving instructional alignment alone may not be sufficient for improving student achievement.