[1] The department is currently part of the Cabinet-level California Labor and Workforce Development Agency,[2] and headquartered at the Elihu M. Harris State Office Building in Oakland.
In other words, California's earliest workers' compensation laws were written as if the IAC members themselves sitting collectively as a panel were supposed to hear the evidence and rule upon each individual claim.
This made no sense for a government agency whose purpose was to divert adjudication of compensation for virtually all work-related injuries from the state judiciary and do it faster and with less formalities than the courts.
[6] After 1951, it became clear that the referees were holding bench trials and the IAC panels were not actually exercising original jurisdiction, but were performing appellate review.
In 1966, the state legislature recognized this reality by enacting a law which divided the IAC into the WCAB and the Division of Industrial Accidents, which later evolved into DWC.
[6] In 1975, DIR began to informally refer to the referees as judges, and the state legislature made that official by enacting appropriate legislation in 1985 which became effective on January 1, 1986.