Impelled by the need to contain health care costs and to ensure that treatment is both necessary and appropriate, most physician organizations have begun to develop standards and guidelines for clinical practice, commonly called practice parameters. Last spring, at the urging of the APA assembly, the board of trustees of the American Psychiatric Association appointed a work group to outline the process to be followed in developing practice parameters for psychiatric disorders. John S. McIntyre, M.D., was appointed chairman of the work group; currently an APA vice-president, he is a former speaker of the APA assembly and in full-time private practice. Recently Dr. McIntyre talked with H&CP Editor John A. Talbott, M.D., about practice parameters and how they will affect the psychiatric field. The following is an edited transcript of their conversation.