TE21, Inc. Benchmark Assessments, Item Bank, Intervention, and Training (TE21 ) - TE21, Inc., Assessments, Interventions, and Training. TE21, Inc. is an education company that offers benchmark assessments aligned to College and Career Ready Standards/Common Core State Standards (CCSS), an item bank of approximately 60,000 standard-based items, intervention solutions, professional development, and a slate of other education improvement efforts for school and districts. Our educators and support staff members are committed to partnering with our customers to improve the education experienc.