The Notice of NIH's Interest in Diversity does not explicitly mention Sexual and Gender Minority (SGM) Populations. (Plainly, NIH lacks data sufficient to classify those groups as underrepresented in the biomedical research workforce.)
But the categories identified in the Notice are meant to be illustrative, not exclusive. As a general matter, NIH's goal is to develop a pool of highly talented scientists from diverse backgrounds and perspectives. NIH’s Office of Extramural Research previously addressed a similar Frequently Asked Question.
For many diversity-related funding initiatives, institutions may provide a description of how a candidate would further the goals of that initiative within a Candidate Eligibility Statement, which provides space for an organization to assert why an individual’s participation would benefit the biomedical research workforce in furtherance of NIH’s mission.
Relatedly, NIH’s Sexual & Gender Minority Research Office coordinates SGM-related research and activities; explore the Office’s website to learn about its current programs and resources.