Code 9: a systematic approach for responding to medical emergencies occurring in and around a hospital. Members of the public expect to receive efficient and appropriate medical care if they become acutely ill or injured while in or around a hospital. Our institution became aware of the need for an organized system to respond to such emergencies involving patients, visitors, local community residents, and hospital employees, both inside the hospital and on the grounds surrounding the building. A search of the literature did not provide information regarding such a response; a survey of surrounding hospitals revealed no such plan in effect in other institutions. We therefore designed a plan to be superimposed onto our existing system for responding to in-house cardiac and respiratory arrests ("codes"). The results after one and one-half years appear encouraging. We recommend the establishment of such an emergency response system in all health care institutions. 