A major obstacle to establishing a computer-stored medical record is the lack of "standards" that would permit government, care providers, insurance companies, and medical computer system developers to share patient data easily. In this position paper, the Board of Directors of the American Medical Informatics Association recommends specific approaches to standardization in the areas of patient, provider, and site of care identifiers; computerized health care message exchange; medical record content and structure, and medical codes and terminologies. The key concept developed in this position paper is that developers and users of computer-stored medical records must embrace existing and tested approaches, despite their imperfections, to progress quickly. This approach to standardization is being coordinated with the American National Standards Institute's Health Informatics Standards Planning Panel. The development of standards is a long-term process involving continued refinement. The proposed standards are an important step toward the goal of better and more efficient health care.