Research suggests that transgender people face high levels of discrimination in society, which may contribute to their disproportionate risk for poor health. However, little is known about whether gender nonconformity, as a visible marker of one's stigmatized status as a transgender individual, heightens trans people's experiences with discrimination and, in turn, their health. Using data from the largest survey of transgender adults in the United States, the National Transgender Discrimination Survey (N = 4,115), we examine the associations among gender nonconformity, transphobic discrimination, and health‐harming behaviors (i.e., attempted suicide, drug/alcohol abuse, and smoking). The results suggest that gender nonconforming trans people face more discrimination and, in turn, are more likely to engage in health‐harming behaviors than trans people who are gender conforming. Our findings highlight the important role of gender nonconformity in the social experiences and well‐being of transgender people.