Many school districts rely on caseload or student to school nurse ratios that are not grounded in evidence-based research. There is a need for a comprehensive workload instrument to describe the work of school nurses that incorporates the complexities of the role and includes acuity, care processes, and social determinants of health. The purpose of this qualitative study was to identify workload activities from a previous Delphi study that can be empirically measured as items for a workload instrument. A nationally representative sample of 27 school nurses participated in four focus groups, describing activities important to the measurement of workload. Focus group input resulted in identification and confirmation of workload activities that impact school nurse workload. Use of the National Association of School Nurses' Framework for 21st Century School Nursing Practice™ was integral in capturing gaps and important workload activities for a potential workload instrument.