Extending quality improvement principles to coordinating patient care among multiple levels of health care service providers has received only limited attention. Referrals function by communicating information about patients' continuing care needs between health care organizations as they transfer responsibility for providing different levels of care. Our evidence suggests several procedural improvements with immediate benefit for improving the quality of referrals. These include employing standardized, written referral forms; assigning responsibility for communication by requiring a signature on each referral; and instituting an information feedback system between sending and receiving health care providers.