This bill aims to eliminate financial barriers to critical breast cancer detection by prohibiting group health plans and health insurance issuers from imposing cost-sharing requirements for diagnostic and supplemental breast examinations. It amends the Public Health Service Act to ensure that medically necessary services, including diagnostic mammography, MRI, and ultrasound, are covered without deductibles, copayments, or coinsurance. The legislation defines diagnostic breast examinations as those evaluating abnormalities and supplemental breast examinations as screenings for individuals with increased risk factors. While prohibiting cost-sharing, the bill allows plans to require prior authorization and applies to "grandfathered" health plans, without superseding stronger state laws. Additionally, it amends the Internal Revenue Code to permit high-deductible health plans (HDHPs) to cover these examinations without a deductible, preserving Health Savings Account (HSA) eligibility. These provisions will take effect for plan years beginning on or after January 1, 2026, enhancing access to essential breast cancer care.