Drug Testing Laws in California

State law (California): The cannabis employment protections in Government Code §12954 apply to employers with five or more employees. Below that threshold they do not apply at all, which is the first thing to establish about any California workplace Source 1State agencyDiscrimination in Employment: Use of Cannabis — frequently asked questions — checked 17 Aug 2026.

State law (California): Where they do apply, an employer may still maintain a drug-free workplace, may still prohibit possession of cannabis at work, and may still prohibit being impaired at work. The protection is about off-duty conduct and about what a particular kind of test result can be used for — not about a right to use cannabis on the job Source 1State agencyDiscrimination in Employment: Use of Cannabis — frequently asked questions — checked 17 Aug 2026.

State law (California): A covered employer generally may not ask a job applicant about prior cannabis use Source 1State agencyDiscrimination in Employment: Use of Cannabis — frequently asked questions — checked 17 Aug 2026. That is a change from long-standing practice and applies to the question itself, not just to what is done with the answer.

State law (California): Employers may still require applicants to take a drug screening, and may still run background checks. What changes is which results can be acted on — see the cannabis section below Source 1State agencyDiscrimination in Employment: Use of Cannabis — frequently asked questions — checked 17 Aug 2026.

State law (California): This is the part that makes California unusual, and it turns on a distinction most drug testing content never makes. A covered employer generally may not discriminate against you based on a test that detects only non-psychoactive cannabis metabolites — the compounds that indicate cannabis was used at some point in the past, not that anyone is impaired now Source 1State agencyDiscrimination in Employment: Use of Cannabis — frequently asked questions — checked 17 Aug 2026.

State law (California): A standard urine drug test is exactly that kind of test. It measures THCA, a metabolite, which is why it can register use from days or weeks earlier. Under §12954 that result alone is generally not something a covered California employer can act on.

State law (California): Where a scientifically valid test detects psychoactive THC, the position is different: an employer may deny employment or take disciplinary action Source 1State agencyDiscrimination in Employment: Use of Cannabis — frequently asked questions — checked 17 Aug 2026. The law draws its line at what the test actually measures, not at whether cannabis is involved.

State law (California): Employers also generally may not penalise you for cannabis use away from work and off the clock Source 1State agencyDiscrimination in Employment: Use of Cannabis — frequently asked questions — checked 17 Aug 2026. Impairment or possession at work remains prohibited.

State law (California): The protections do not apply to everyone. Four exemptions are stated: employers with fewer than five employees; positions requiring a federal background investigation or security clearance; employees in the building and construction trades; and any situation where federal or state law requires drug testing Source 1State agencyDiscrimination in Employment: Use of Cannabis — frequently asked questions — checked 17 Aug 2026.

State law (California): That last exemption is the widest in practice. If your role is covered by a federal testing requirement, the California protections give way to it — so a safety-sensitive transportation worker in California is in substantially the same position as one in any other state.

Federal (DOT): If your role is DOT-regulated, nothing on this page changes your test. The panel, the cutoffs, the collection procedure and the consequences of a positive result are all set federally, and California's cannabis protections expressly do not reach situations where federal law requires testing Source 1State agencyDiscrimination in Employment: Use of Cannabis — frequently asked questions — checked 17 Aug 2026.

Federal (DOT): Legal cannabis in California has never changed what a DOT test reports or what a positive means for a safety-sensitive role. If you are a commercial driver, a pilot, or in another regulated role, read the federal guides rather than this page.