Gender expansive individuals of all ages are at an elevated risk for mental and physical health problems compared not only to the general population, but also to lesbian, gay, and bisexual individuals. Yet mental healthcare providers tend to be underprepared to provide services to this population, which is due in part to the dearth of scholarship on how to provide competent care to genderexpansive people. The present article introduces themes and terminology crucial to working with this population, as well as three case studies-two individuals and one family-highlighting the nuances inherent in workng with gender expansive clients. We conclude by offering ways to conceptualize each case, and by highlighting certain areas that we believe deserve specific considerations from care providers.gender confirmation, gender expansive, gender nonconforming, nonbinary, transgender From the increasingly diverse depiction of gender-expansive characters on television (i.e., Elektra Abundance, a Black transgender woman on Pose or Taylor, a White nonbinary hedge fund manager on Billions) to news cycles in the United States (US) focused on "bathroom bills" and restricting gender identity to sex assigned at birth, the past 5 years have yielded a seismic shift in our cultural understanding of transgender issues. Terminology related to gender is rapidly evolving, but at the time of writing this article, gender expansive and/or gender diverse are preferred umbrella terms for individuals who may embody a wide array of diverse gender identities and presentations such as transgender (i.e., often more a "binary" gender identity: trans women and men) or nonbinary gender identity (i.e., an identity that deliberately transcends, rejects, or hybridizes traditional expectations of masculinity or femininity: genderqueer, gender fluid, gender nonconforming, androgynous, and agender, to name a few). Although self-concept, identity labels, and gender presentation vary widely across groups, one commonality of