© 2018 John Wiley & Sons Ltd and The Association for the Study of Medical Education Objectives: The purpose of this study was to conduct a scoping review of the literature and to categorically map a 15-year trajectory of US undergraduate medical education rationales for and approaches to expanding under-represented minority (URM) physician representation in the medical workforce. Further aims were to comparatively examine related justifications and to consider international implications. Methods: From 1 June to 31 July 2015, the authors searched the Cochrane Library, ERIC, PsycINFO, PubMed, Scopus, Web of Science and Google Scholar for articles published between 2000 and 2015 reporting rationales for and approaches to increasing the numbers of members of URMs in undergraduate medical school. Results: A total of 137 articles were included in the scoping review. Of these, 114 (83%) mentioned workforce diversity and 73 (53%) mentioned concordance. The patient–physician relationship (n = 52, 38%) and service commitment (n = 52, 38%) were the most commonly cited rationales. The most frequently mentioned approaches to increasing minority representation were pipeline programmes (n = 59, 43%), changes in affirmative action laws (n = 32, 23%) and changes in admission policies (n = 29, 21%). Conclusions: This scoping review of the 2000–2015 literature on strategies for and approaches to expanding URM representation in medicine reveals a repetitive, amplifying message of URM physician service commitment to vulnerable populations in medically underserved communities. Such message repetition reinforces policies and practices that might limit the full scope of URM practice, research and leadership opportunities in medicine. Cross-nationally, service commitment and patient–physician concordance benefits admittedly respond to recognised societal need, yet there is an associated risk for instrumentally singling out members of URMs to fulfil that need. The proceedings of a 2001 US Institute of Medicine symposium warned against creating a deterministic expectation that URM physicians provide care to minority populations. Our findings suggest that the expanding emphasis on URM service commitment and patient–physician concordance benefits warrants ongoing scrutiny and, more broadly, represent a cautionary tale of unintended consequences for medical educators globally.