This legislation, titled the Cancer Drug Parity Act of 2025, amends the Employee Retirement Income Security Act of 1974 (ERISA) to mandate that group health plans provide equitable cost-sharing for oral anticancer drugs. Specifically, it requires that cost-sharing for prescribed, patient-administered oral anticancer medications, which are FDA-approved and medically necessary, be no less favorable than the cost-sharing applied to anticancer medications administered intravenously or by injection by a health care provider. These provisions are set to apply to plan years beginning on or after January 1, 2026. The bill includes safeguards to prevent plans from circumventing this parity, prohibiting changes that would increase out-of-pocket costs or reclassify benefits for anticancer medications. It clarifies that the act does not require the use of oral medications over others, allows for prior authorization, and does not supersede stronger state laws. Furthermore, it directs the Comptroller General of the United States to conduct a study within two years of enactment, assessing the impact of these changes on patient out-of-pocket costs for oral anticancer medications and providing recommendations to Congress.