In 1996, voters approved Proposition 215, which legalized the use of medicinal cannabis in California. Since the proposition was passed most regulation was done by local governments.
In 2015, the California legislature enacted three bills —AB 243 (Wood, Chapter 688); AB 266 (Bonta, Chapter 689); and SB 643 (McGuire, Chapter 719)—that collectively established a comprehensive state regulatory framework for the licensing and enforcement of cultivation, manufacturing, retail sale, transportation, storage, delivery and testing of medicinal cannabis in California. This regulatory scheme was known as the Medical Cannabis Regulation and Safety Act (MCRSA). Not long after, Senate Bill 837 (Committee on Budget, Chapter 32, Statutes of 2016) built upon the MCRSA framework and added comprehensive environmental safeguards that require the State Water Resources Control Board, in consultation with the Department of Fish and Wildlife, to adopt principles and guidelines governing the use of water for cannabis cultivation with the goal of protecting streams and rivers from illegal diversion.
In November of 2016, voters approved Proposition 64, the Adult Use of Marijuana Act (AUMA). Under Proposition 64, adults 21 years of age or older can legally grow, possess, and use cannabis for non-medicinal purposes, with certain restrictions. In addition, beginning on January 1, 2018, AUMA makes it legal to sell and distribute cannabis through a regulated business.
In June 2017, the California State Legislature passed a budget trailer bill, Senate Bill 94 (Chapter 27), that integrated MCRSA with AUMA to create the Medicinal and Adult‐Use Cannabis Regulation and Safety Act (MAUCRSA) contained in division 10 of the Business and Professions Code (§26000 et seq.). Under MAUCRSA, a single regulatory system governs the medical and adult use cannabis industry in California.