The purpose of this report is to describe the technical qualities of the 2018-2019 operational administration of the English language arts/literacy (ELA/L) and mathematics assessments in grades 3 through 8 and high school. New Meridian, in coordination with multiple states and vendors, developed an alternate form of the summative assessment to meet the needs for shorter testing times desired by several states. Through extensive research and guidance from the Technical Advisory Committee, the alternate blueprint was available in spring 2019. The ELA/L assessments focus on reading and comprehending a range of sufficiently complex texts independently and writing effectively when analyzing text. The mathematics assessments contain tasks that measure a combination of conceptual understanding, applications, skills, and procedures. Mathematics constructed-response items consist of tasks designed to assess a student's ability to use mathematics to solve real-life problems. In both content areas, students also demonstrate their acquired skills and knowledge by answering selected-response items and fill-in-the-blank questions. The summative assessments are designed to achieve several purposes. First, the tests are intended to provide evidence to determine whether students are on track for college- and career-readiness. Second, the tests are structured to access the full range of Common Core State Standards (CCSS) and measure the total breadth of student performance. Finally, the tests are designed to provide data to help inform classroom instruction, student interventions, and professional development. This technical report includes the following topics: (1) background and purpose of the assessments; (2) test development of items and forms; (3) test administration, security, and scoring; (4) student characteristics; (5) classical item analyses and differential item functioning; (6) reliability and validity of scores; (7) item response theory (IRT) calibration and scaling; (8) performance level setting; (9) development of the score reporting scales and student performance; (10) student growth measures; and (11) quality control procedures. [For "New Meridian Technical Report 2018-2019," see ED604241.]