The Ensuring Lasting Smiles Act requires health insurance plans to cover diagnosis and treatment services for congenital anomalies and birth defects affecting the eyes, ears, teeth, mouth, or jaw, including reconstructive surgery, dental work, and follow-up care. The coverage applies to both group health plans and individual insurance policies and takes effect for plan years beginning January 1, 2026. Insurance companies can still charge standard copayments and deductibles comparable to other medical services, but cannot impose additional restrictions specific to birth defect treatment. By January 1, 2026, insurers must notify members about this new coverage. The bill excludes purely cosmetic surgery unrelated to treating an actual birth defect, and directs the Secretary of Health and Human Services to study provider network adequacy and patient costs by December 31, 2027, to ensure people can actually access these services.