Amends the Illinois Insurance Code. Provides that a group or individual policy of accident and health insurance or managed care plan that is amended, delivered, issued, or renewed on or after January 1, 2026 shall provide coverage for medically necessary general anesthesia, regardless of the duration, for any procedure covered by the policy, and that medical necessity shall be determined by the attending anesthesiologist or licensed anesthesia provider. Provides that an individual or group policy of accident and health insurance is prohibited from denying payment or reimbursement for anesthesia services solely because the duration of care exceeded a preset time limit. Amends the State Employees Group Insurance Act of 1971, the Counties Code, the Illinois Municipal Code, the School Code, the Health Maintenance Organization Act, the Limited Health Service Organization Act, the Voluntary Services Plans Act, and the Illinois Public Aid Code to require coverage under those provisions. Effective immediately.