The de-adoption of evidence-based practices (EBPs) is a largely understudied topic. The present study examined factors related to the de-adoption of an EBP for students exposed to traumatic events in a large urban school district. Qualitative interviews conducted with school clinicians and district administrators 2 years after the district embarked on a large-scale rollout of the EBP distinguished between factors that impacted partial de-adoption after 1 year (phase 1) and complete de-adoption by the district after 2 years (phase 2). Phase 1 factors included organizational consistency, workforce stability, prior success, positive student outcomes, school- and district-level supports, innovation-setting fit, and innovation-related issues. Phase 2 factors included district-level leadership changes, financial and workforce instability, and shifting priorities. Study results suggest that sustainment-enhancing strategies should be included in the early stages of program implementation to most effectively adapt to school- and system-level changes.