Transgender individuals worldwide are bound to the necessity of the provider’s letter—a letter from healthcare professional certifying the validity of their identity—for medical care and legal recognition. The use of the provider’s letter continues, despite decades of community pushback, a lack of any evidence of efficacy or positive effect of the requirement, and multiple literatures supporting its unethical and damaging impacts on the trans community. This project uses three approaches, in the form of three separate but thematically connected articles, to understand the letter and its current usage in the trans medical and legal world. The first article defines the providers letter and performs an integrated historical review of the letter and the bodies of literature that have engaged with it; bioethics, critical literatures of medicalization/pathologization, and legal scholarship. This review concludes that the letter, rather than being a supportive or helpful practice, is used to control trans bodies and performances of gendered subjectivity. Further, that the justification of the letter focuses on the specter of regret, which has not been supported by evidence to be a legitimate concern. The second article digs into the history of the letter as an object, revealing its origins as a part of the application for a transvestite certificate in early 20th century Germany. This article focuses on sexologist Dr. Magnus Hirschfeld as the creator of the modern understanding of the letter, and its use in the application for the transvestite certificate, a pragmatic solution to the problem of presumed transvestites disturbing the peace. Hirschfeld’s pupil, Dr. Harry Benjamin, brought the letter to the United States and served as the architect for early trans medicine in the mid 20th century, so its Germanic origins are deeply relevant to the modern practice. The final article focuses on an alternative approach to transgender medicine, first laying out the issues with the current medical model, then laying out an alternative model, the gender wellness model. This model rests on the idea that all people have an optimum level of gender wellness, and for some, reaching that optimum level may require intervention. While the letter is a complex object that resists simple categorization, understanding what it was created to do and how it functions practically in the legal and medical realm opens a variety of productive avenues for exploration.