The downsizing of residencies and the migration of residents to outpatient settings create an increasing need to protect residents' educational experiences and to maintain standards of hospital care. Some hospitals have solved this dilemma by using mid-level practitioners (MLPs), including physician assistants (PAs), to augment the diminished staffs of residents in their surgical residencies. The authors describe how their hospital has done so. Their surgical PA program, begun in 1979, seeks to meet the hospital's expectations for in-house coverage of surgical patients, to protect the educational integrity of the physician residency program in surgery, to allow protected time for residents' conferences and clinics, and to prepare residents for future practice in multidisciplinary teams. The PA and residents' services are partly separated, which reduces the potential for resident-PA conflict. Responsibilities for both residents and PAs are stratified (junior vs senior status). Both services are teaching services, which helps motivate PAs to be committed to the service and helps foster the equality between residents and PAs that the program strives for. The residents have come to value the PAs, and the program's goals have been achieved, including protecting time for residents' education and maintaining humane on-call schedules for residents. The authors discuss job satisfaction, turnover, and the hard financial realities of paying for PAs' salaries, benefits, and educational programs, as well as the loss of Medicare DME and IME reimbursements when a PA replaces a resident. Ways some of these costs can be recovered are outlined. The authors conclude with recommendations on how to deal with six key issues of PA or other MLP programs: need for institutional commitment; importance of local circumstances; emphasis on partnership, not competition, between PAs and residents; value of an education component; need to build a cohesive program, and the importance of effective PA leadership.