In this section the following words have the meanings indicated. “Authorized prescriber” has the meaning stated in § 12-101 of the Health Occupations Article. “Maintenance drug” means a drug anticipated to be required for 6 months or more to treat a chronic condition. This section applies to: insurers and nonprofit health service plans that provide coverage for drugs under health insurance policies or contracts that are delivered or issued for delivery in the State to employers or individuals on a group or individual basis; and health maintenance organizations that provide coverage for drugs under contracts that are delivered or issued for delivery in the State to employers or individuals on a group or individual basis. This section does not apply to an insured or enrollee who is a resident of a nursing home. An entity subject to this section shall allow an insured or enrollee, if authorized by an authorized prescriber, to receive up to a 90-day supply of a maintenance drug in a single dispensing of the prescription. The provisions of paragraph (1) of this subsection do not apply to the first prescription or change in a prescription for a maintenance drug that the authorized prescriber prescribes for the insured or enrollee. Whenever an entity subject to this section increases the co-payment for a single dispensing of a prescription in a supply in excess of 30 days, the entity shall also proportionately increase the dispensing fee to the pharmacist for the prescription.