This scoping review maps over 40 years of peer-reviewed Omaha System literature to assess the breadth and evolution of evidence supporting its use in research and practice. The Omaha System is a standardized terminology describing client needs, interventions, and outcomes, applied across diverse clinical, community, and research settings in the U.S. and internationally. Prior reviews outlined three phases of publications through 2019, but their results were not aggregated or extended to recent work. Using Joanna Briggs Institute methods, five databases—MEDLINE, CINAHL Complete, Web of Science, APA PsycINFO, and Academic Search Ultimate—were searched for English-language articles from 1982–2025. Reference lists from the Omaha System website were also screened. After removing duplicates, 437 unique studies were reviewed through a two-phase Covidence screening, with data extraction by two independent reviewers. Preliminary findings include 149 studies from prior reviews, 146 newly identified pre-2020 studies, and 142 published between 2020–2025. This growing and diverse body of work will provide a comprehensive evidence map, reveal knowledge gaps, and guide future systematic reviews.
