This updated volume introduces the field of pediatric gender health, which widens the scope of the gender affirmative model to support the the gender health of transgender and gender diverse (TGD) pre- and peripubescent youth and their families. With the devastating increase in legislative care bans and media attacks on TGD youth since the first edition of this book was published, many health care systems have shut down care centers that have been providing high quality pediatric gender health care. The weaponization of “gender affirming” terminology has served to deny the experiences of TGD youth, while discrimination, verbal harassment, and violence toward TGD communities is on the rise. This book provides guidance to pediatric providers and trainees who aim to deliver up-to-date, empirically informed best clinical practices. At the same time, the text is accessible to educators, parents, and families of TGD youth. The chapters provide a fully updated literature review, summarize key epistemological advances, and incorporate detailed interventions and extensive case examples, which emphasize the importance of the integration of cultural humility, intersectionality, and multicultural approaches to therapy. Research continues to demonstrate the benefit of pediatric gender health care for TGD youth and their families. This timely second edition grounds readers in the rigorous empirical research needed to inform the provision of pediatric gender health in the face of increasing challenges in health care for TGD youth.