Louisa Moats’ LETRS course grew from fewer than 25,000 enrollees in 2020 to 700,000 in 2025, Lexia says. As science-of-reading laws spread to 42 states and D.C., its effect on student reading remains uncertain; study results are not expected until 2029.
LETRS (Language Essentials for Teachers of Reading and Spelling) is a 155-hour course covering language theory and cognitive science, including how speech sounds connect to letters, how words are built and how they are spelled. Twenty-three states have purchased it. Public contracts suggest statewide rollouts can cost up to $1,700 per educator, excluding substitute teachers, planning time, coaching and administration.
An Institute of Education Sciences report found that LETRS training improved teachers’ understanding of language but did not improve student outcomes. Moats says one year was too soon to see an effect on achievement. A $4 million, five-year randomized study is underway. Mississippi’s fourth-grade NAEP reading score rose 10 points from 2013 to 2019 after LETRS training began, but the state also introduced coaching, accountability, screening and intervention, and retained some third-graders.
