As transgender and gender-diverse people are gaining increased visibility in clinical settings, clinicians are requesting better guidance on providing affirming care to improve the mental health and well-being of these patients. In particular, more direction is needed on whether, when, and how to diagnose and treat borderline personality disorder among gender minorities, partially in response to beliefs among some mental health clinicians that a gender minority identity may be a manifestation of identity diffusion. In this Perspectives article, we argue that gender minority identity, even when fluid, is rarely a sign of identity diffusion. By taking a careful history of a patient's gender identity development, the clinician can clarify and gain more conviction regarding the presence of a patient's gender minority identity. Moreover, multiple stigma-related stressors experienced by gender minorities may produce symptoms and behaviors that can mimic or be consistent with certain diagnostic criteria for borderline personality disorder. We therefore conclude with recommendations for adopting a gender-affirming framework to treat borderline personality symptoms when present among gender minority patients, with implications for future research and practice.