A CWCI Research Update Report provides new data on prescription drug utilization and reimbursement trends, based on 5.85 million prescriptions dispensed to California injured workers from 2011 through June 2020. The report looks at changes in the distribution of prescriptions and payments by therapeutic drug group; details opioid utilization trends for AY 2007 -2018 claims at 24 months post injury using four different metrics; and measures pre- and post-formulary shifts in the mix of prescription drugs and payments among the formularys drug categories.