A law in some states which requires a managed care organization, such as an HMO, to grant participation to any provider who is legally qualified as a practitioner and who is willing to become a member of the organization. Such laws are enacted to protect the patient’s freedom of choice. However they often interfere seriously with the efforts of the managed care organization to achieve high quality and efficiency by limiting its provider network to caregivers with the best performance records, to hospitals in convenient geographic locations, and to selected pharmacies.