This qualitative study examined special education teachers' perceptions of student success in online instruction during the COVID-19 pandemic school closures to isolate the key determinants in the differential student outcomes reported by the teachers. Data were collected from 16 teachers in the U.S. state of California using semi-structured interviews and analyzed using thematic coding. The six themes that emerged from the data were that the key determinants of student outcomes were variables related to teacher, school administrator, district, student, parent, and pedagogy. The study showed that underlying deficit thinking in school professionals, lack of planned support for those parents and students needing the most support, and limited range of teaching practices were responsible for the equity gap seen in the differential student outcomes. Recommendations include training school administrators, providing parent support to access technology, addressing needs of non-English speaking families, expanding pedagogical practices, and planning for students with the most extensive support needs.