This report provides an update on the state of the research on testing accommodations. Previous reports by the National Center on Educational Outcomes (NCEO) have covered research published since 1999. In this report, we summarize the research published in 2020. During 2020, 11 research studies addressed testing accommodations in the U.S. K-12 education system. The research also highlights important emerging issues including the role of technology in facilitating accessibility for students with disabilities through built-in accommodations and in considering needed practices for applying technologies. [For the 2019 report, see ED620540.]