He is a fellow of the American Psychological Association (APA) and a past president of APA’s Division 44 (the Society for the Psychological Study of Lesbian, Gay, Bisexual, and Transgender Issues), and of Section VII (Clinical Emergencies and Crises) of APA’s Division 12 (Society of Clinical Psychology). He served on the APA Task Force that developed the Guidelines for Psychological Practice with Transgender and Gender Nonconforming People. He has conducted research with TGNC people and is the lead author on the seminal paper on the minority stress model for transgender inidividuals. In 2015, he was awarded an American Psychological Association Presidential Citation for his work. A primary focus of his clinical practice involves work with TGNC adolescents and adults.