A form of health care plan in which certain physicians are designated by a third party payer as preferred providers whom the payer has concluded are the most cost-effective. When a beneficiary elects to receive care from these physicians, the physicians’ charges are paid in full—there is no additional charge to the beneficiary. The beneficiary may elect to obtain care from other physicians, but if she does, there is a financial penalty to the beneficiary—she must pay part of the charges.