Concurrent Classes: A Popular (and Challenging) Model The paradigm of K-12 education shifted nearly overnight due to the COVID-19 pandemic. Many districts immediately embraced full remote learning for the remainder of the 2019-20 school year. Some have continued in that mode for the first half of the 2020-21 school year. Other districts instituted (or have moved to) a K-12 Blended Learning model, with some combination of in-person and online learning.