CWCI's analysis of changes in the volume and reimbursement of California workers' comp professional medical services from 2013-2018, which includes the 4-year transition to the RBRVS fee schedule that began in 2014. The study reviews data from nearly 36 million medical services rendered to injured workers during that period to measure shifts in the mix of services and payments across and within 9 major services categories, and discusses the underlying changes to the fee schedule that affected those moves.