Requires health plans that cover diagnostic or supplemental breast exams to eliminate patient cost‑sharing (deductibles, copayments, coinsurance) for those exams. Plans may still use prior authorization or other utilization controls, stronger State laws remain in force, and an IRS safe harbor preserves high‑deductible HSA eligibility even if these exams have no deductible. The rule applies to plan years beginning on or after January 1, 2026.