This section applies to: insurers and nonprofit health service plans that provide coverage for substance use disorder benefits or prescription drugs under individual, group, or blanket health insurance policies or contracts that are issued or delivered in the State; and health maintenance organizations that provide coverage for substance use disorder benefits or prescription drugs under individual or group contracts that are issued or delivered in the State. An insurer, a nonprofit health service plan, or a health maintenance organization that provides coverage for substance use disorder benefits under the medical benefit or for prescription drugs through a pharmacy benefits manager is subject to the requirements of this section. An entity subject to this section may not apply a prior authorization requirement for a prescription drug: when used for treatment of an opioid use disorder; and that contains methadone, buprenorphine, or naltrexone.