What is a Gender Therapist?
Excerpt below from World Professional Association for Transgender Care, Standards of Care Version 8, 2022

Recommendations in Adult Assessment Chapter
5.1- We recommend health care professionals assessing transgender and gender diverse adults for physical treatments:
5.1.a- are licensed by their statutory body and hold, at a minimum, a master’s degree or equivalent training in a clinical field relevant to this role and granted by a nationally accredited statutory institution.
5.1.b- for countries requiring a diagnosis for access to care, the health care professional should be competent using the latest edition of the World Health organization's International Classification of diseases (ICd) for diagnosis. In countries that have not implemented the latest ICd, other taxonomies may be used; efforts should be undertaken to utilize the latest ICd as soon as practicable.
5.1.c- are able to identify co-existing mental health or other psychosocial concerns and distinguish these from gender dysphoria, incongruence, and diversity.
5.1.d- are able to assess capacity to consent for treatment.
5.1.e- Have experience or be qualified to assess clinical aspects of gender dysphoria, incongruence, and diversity.
5.1.f- undergo continuing education in health care relating to gender dysphoria, incongruence, and diversity.
5.2- We suggest health care professionals assessing transgender and gender diverse adults seeking gender-affirming treatment liaise with professionals from different disciplines within the field of transgender health for consultation and referral, if required.​

---END WPATH Standards of Care Version 8 Text​ Excerpt P. S30
The 2022 WPATH SOC8 also has specific recommendations around knowledge for child and adolescent providers in each of those sections.
The formal certification as a "WPATH GEI SOC8 Certified Member" through the Global Education Initiative (GEI) started in 2017. The program provides enhanced training and a way patients and other providers can feel secure in referring to highly knowledgeable providers. The organization is aware that this process can be cost-prohibitive to lower income clinicians, many of whom are BIPOC, disabled therapists, non binary & trans-identified clinicians who cannot travel to trainings. WPATH is working to address inequities. Lisette hopes to improve the accessibility of the certification process by offering low-fee slots in mentoring groups.
A Gender Specialist is "...an active practitioner in psychotherapy, counseling, or education directly oriented toward gender-identity issues. It is recommended that care providers interested in establishing themselves as Gender Specialists undergo a minimum of two years of direct supervision or consultation with a practicing Senior Gender Specialist who is recognized as having advanced experience in providing consultation to peer practitioners."
Transgender Care: Recommended Guidelines, Practical Information & Personal Accounts Gianna E. Israel & Donald E. Tarver II, M.D., 1997, Pg 12