In our 2018 commentary (D. Chen, Edwards-Leeper, Stancin, & Tishelman, 2018), we highlighted the increasing acceptance of gender affirmative approaches as the gold standard in pediatric transgender health care (Edwards-Leeper, Leibowitz, & Sangganjanavanich, 2016; Hidalgo et al., 2013; Substance Abuse and Mental Health Services Administration, 2015), while also acknowledging the limited evidence base informing care for transgender and gender diverse (TGD) youth. This relative lack of research represents a critical gap given the growing numbers of TGD youth presenting for gender-affirming care (M. Chen, Fuqua, & Eugster, 2016;Wood et al., 2013) and the subsequent surge in need for pediatric psychologists to serve in critical roles on interdisciplinary gender health teams (D. Chen et al., 2016;Cousino, Davis, Ng, & Stancin, 2014;Tishelman et al., 2015), the number of which have grown exponentially in the last decade (Hsieh & Leininger, 2014). About 20 attendees involved in the care of TGD youth met informally at the 2019 Society of Pediatric Psychology Annual Conference in New Orleans earlier this year. We discussed the varied roles we each hold in our home institutions and how we interface with TGD youth and their families clinically and with our interdisciplinary colleagues who may be providing medical and surgical care for these youth. We also reviewed the respective models of care used, which differed despite sharing a general affirmative stance. This meeting occurred with less than 2 weeks' notice and without dedicated time scheduled at the conference, revealing substantial interest from the broader pediatric psychology community in the clinical care of TGD youth. This interest likely also stems from an understanding that most pediatric psychologists will encounter TGD youth during the course of clinical practice, whether in clinics providing specialty care to TGD youth, primary care, or other pediatric specialized services, as gender diversity Editor's Note. This is an introduction to the special issue "Advancing the Practice of Pediatric Psychology With Transgender Youth." Please see theTable of Contents here: