Each year, the Houston Independent School District (HISD) offers a summer education program designed to assist students with a variety of instructional needs. In 2021, centrally coordinated summer school programs included accelerated instruction for State of Texas Assessments of Academic Readiness (STAAR) and STAAR End-of-Course (EOC) re-testers; bilingual or English as a Second Language (ESL) classes for English Learners (ELs); credit accrual/recovery for students needing to graduate; Extended School Year (ESY) services; Promotion/Retention classes; and other school-based programs. The summer education program supports HISD's Board Goal 3: Academic Growth. This report shows student enrollment and outcomes for students who attended summer school in 2021 based on either retention status at the end of spring 2020 or for other reasons, such as academic enrichment. This report addresses eligibility, enrollment, attendance, and outcomes for the 2021 HISD summer school program.