This test review aims to provide a critical evaluation of the English Language Proficiency Assessment for the 21st Century (ELPA 21), a large-scale, standards-based English language proficiency testcurrently used in eight participating member states. The ELPA 21 assessment system was developed by a consortium to help English language learner (ELL) students acquire the academic English language required for accessing content knowledge so they are prepared for college and career. The ELPA 21 assessments are administered fully online. It includes a screener assessment and a summative assessment for ELL students from kindergarten to twelfth grade. The ELPA 21 summative and screener tests were officially launched in the spring of 2016 and in the fall of 2016, respectively. The results are used to determine placement in English language services and reclassification of ELL students, measure ELL students' progress in English language development, and design professional development and formative assessments. Based on the documents and practice items available online, the ELPA 21 test appears to be a useful instrument for evaluating and supporting ELL students' English language development. However, possibly because of its newness, publicly available materials about its validation research are limited. The lack of published validation research casts some doubts on the test's quality. When the research results, along with any updated information are available, a follow-up review would be necessary to ensure that the ELPA 21 test is serving ELL students properly.