**2. Methods**

We began our literature review in August 2020 by conducting a search for "residency program merger" on PubMed and Google Scholar from all years available (1968–2020). There were a total of 33 results for this search query. We then narrowed down these results to those only describing mergers of graduate medical education. Additionally, we incorporated several papers that did not appear in our original search, but were listed as references in one or more publications that appeared in our search. Our aim was to include as many examples of residency mergers to develop a comprehensive view of graduate medical education mergers and the successes and challenges that have been identified.
