INTRODUCTION: Interest is growing in specialty-specific assessments of student candidates based on clinical clerkship performance to assist in the selection process for postgraduate training. The most established and extensively used is the emergency medicine (EM) Standardized Letter of Evaluation (SLOE), serving as a substitute for the letter of recommendation. Typically developed by a program's leadership, the group SLOE strives to provide a unified institutional perspective on performance. The group SLOE lacks guidelines to direct its development raising questions regarding the assessments, processes, and standardization programs employ. This study surveys EM programs to gather validity evidence regarding the inputs and processes involved in developing group SLOEs. METHODS: A structured telephone interview was administered to assess the input data and processes employed by United States EM programs when generating group SLOEs. RESULTS: With 156/178 (87.6%) of Accreditation Council of Graduate Medical Education-approved programs responding, 146 (93.6%) reported developing group SLOEs. Issues identified in development include the following: (1) 84.9% (124/146) of programs limit the consensus process by not employing rigorous methodology; (2) several stakeholder groups (nurses, patients) do not participate in candidate assessment placing final decisions at risk for construct under-representation; and (3) clinical shift assessments don't reflect the task-specific expertise of each stakeholder group nor has the validity of each been assessed. CONCLUSION: Success of the group SLOE in its role as a summative workplace-based assessment is dependent upon valid input data and appropriate processes. This study of current program practices provides specific recommendations that would strengthen the validity arguments for the group SLOE.