This paper describes the implementation of clinically defined episodes of care and the introduction of an episode-based summary list of patient problems across Mayo Clinic Rochester in 1996 and 1997. Although Mayo's traditional paper-based system has always relied on a type of 'episode of care' (called the "registration") for patient and history management, a new, more clinically relevant definition of episode of care was put into practice in November 1996. This was done to improve care management and operational processes and to provide a basic construct for the electronic medical record. Also since November 1996, a computer-generated summary list of patient problems, the "Master Sheet Summary Report," organized by episode, has been placed in all patient histories. In the third quarter of 1997, the ability to view the episode-based problem summary online was made available to the 3000+ EMR-capable workstations deployed across the Mayo Rochester campus. In addition, the clinically oriented problem summarization process produces an improved basic "package" of clinical information expected to lead to improved analytic decision support, outcomes analysis and epidemiological research.