California Code, Health and Safety Code - HSC § 1385.0032

(a) Notwithstanding any other law, a pharmacy benefit manager shall not enter into, amend, enforce, or renew a contract on or after January 1, 2026, with manufacturers that do business in California that implement implicit or express exclusivity for those manufacturers' drugs, unless the pharmacy benefit manager can demonstrate the extent to which exclusivity results in the lowest cost to the payer, and the lowest cost sharing for the plan participant.

(b) Notwithstanding any other law, a pharmacy benefit manager shall not enter into, amend, enforce, or renew a contract on or after January 1, 2026, with pharmacies or pharmacy services administration organizations that do business in California that expressly or implicitly restrict, or impose implicit or express exclusivity on, nonaffiliated pharmacies' ability to contract with employers and payers.

(c) Contracts entered into pursuant to this section shall be open for inspection and audit by the department.