The World Professional Association for Transgender Health (WPATH) is the leading authority in the field of gender medicine. Its guidance is routinely used by top medical associations in the U.S. and abroad, while its standards of care inform insurance companies’ approach to coverage policies. But behind closed doors, top WPATH doctors discussed, and at times seemed to challenge, the organization’s own published guidelines for sex change procedures and acknowledged pushing experimental medical interventions that can have devastating and irreversible complications.