Discipline reformers claim that suspensions negatively affect suspended students, while others suggest reforms have unintended consequences for peers. Using student panel data from the School District of Philadelphia, we implement student fixed effects and instrumental variable (IV) strategies to examine the consequences of suspensions for offending students and their peers. A suspension decreases math and reading achievement for suspended students. The effects are robust to IV estimates leveraging a district-wide policy change in suspension use. Suspensions are more salient for students who personally experience suspension than for their peers. Exposure to suspensions for more serious misconduct has very small, negative spillovers onto peer achievement, but does not change peer absences.