This study examines the effects of English Learner (EL) status on subsequent Special Education (SPED) placement. Through a research-practice partnership, we link student demographic data and initial English proficiency assessment data across seven cohorts of test takers and observe EL and SPED programmatic participation for these students over seven years. Our regression discontinuity estimates consistently differ substantively from results generated through regression analyses. We find evidence that the effect of EL status on SPED placement was either null or tied to slight under-identification. Our results suggest that under-identification occurred two years after EL classification. We also find that EL status led to under-identification for Spanish speakers and proportionate representation for Mandarin/Cantonese speakers and speakers of all other languages. [Additional funding was provided by the California Education Partners.]