Retrospective payment is reimbursement paid to the provider after health care services are renderedCost-based reimbursement would encompass which process? Payer agrees to pay for costs directly related to providing an acceptable standard of health services Provider bills the payer for the full charges of the health care related goods and services Payer negotiates a reduced rate that is less than the charge non- negotiated flat fee reimbursement by the payer that is less than the provider's full charge