Transgender individuals have been identified as having greater rates of substance use. Previous research often focused on the intersection of HIV risk and substance use on specific age ranges or on how minority stress and discrimination relate to substance use. Using data from the 2015 United States Transgender Survey, our study is one of the first to explore the relationship among gender identity, age, the role of medical transition, and the use of marijuana within the transgender community. A deeper understanding of the relationship of these variables will benefit the transgender community by allowing for more thorough and accurate assessment protocols for individuals seeking medical transition. Our study used descriptive statistics to examine the intersection of gender identity, age, and use of alcohol, cigarettes, and marijuana. ANOVAs were completed to determine significant impact of gender identity, age, cigarette and alcohol use, and medical transition on the use of marijuana. Significantly, we found that 37% of marijuana use can be predicted by gender identity, age, medical transition, and alcohol and cigarette use. Individuals who experienced any surgical transition reported significantly more marijuana use compared with individuals with no history of surgical transition. Our study highlights the need for more in-depth research about the complicated factors that relate to the impact of transition-related medical care and the intersection of gender identity and age.