The "Defending Affordable Prescription Drug Costs Act" aims to protect 340B covered entities and their contract pharmacies from discriminatory practices by health insurers, pharmacy benefit managers, and pharmaceutical manufacturers. The bill prohibits these entities from engaging in various discriminatory actions, including:

1. Establishing lower reimbursement rates for 340B drugs compared to non-340B drugs based solely on the drug's 340B status.
2. Imposing different fees, chargebacks, or conditions on reimbursement for 340B covered entities than those applied to non-340B entities.
3. Denying or limiting participation in pharmacy networks based on 340B status.
4. Imposing inconsistent audit requirements related to inventory management systems.
5. Requiring claims-level data that identifies 340B drugs as a condition of reimbursement, unless mandated by the Centers for Medicare and Medicaid Services.
6. Interfering with a 340B covered entity's choice to use a contract pharmacy for drug distribution or dispensing.
7. Imposing additional charges or restrictions on patients who choose to receive 340B drugs compared to non-340B drugs.
8. Excluding any 340B covered entity from networks or refusing to contract with them for reasons not applicable to non-340B entities.

The act also mandates that 340B covered entities submit annual reports detailing their participation in the 340B program, including financial data and the impact of savings on patient care.

Additionally, the act grants the office of the state auditor general the authority to investigate compliance and enforce the provisions of the chapter. Violations of the act will be treated as violations of existing laws regarding deceptive and unfair sales practices. The act is set to take effect on October 1, 2025.