2022
Sex-change surgery is an adult procedure under medical-council ethics.
Official sources
Asia. Medical Council 18-plus surgery ethics.
Full official record
The Medical Council of Thailand’s 2022 professional-ethics regulation on sex-change treatment, published in the Royal Gazette on 23 November 2022, sets who may receive sex-change surgery. A person aged 18 but not yet 20 needs guardian consent. A person aged 20 or over may proceed without that extra consent. Surgery under 18 is not permitted under this regulation. That is an 18-plus surgery floor.
Clause 6 of the Medical Council regulation is the surgery-age rule. Hormones appear in the regulation as part of the adult treatment pathway.
Schools detail
Section 6 of the Prevention and Solution of the Adolescent Pregnancy Problem Act B.E. 2559 (2016) requires educational establishments to provide age-appropriate sexuality studies, to recruit and develop teachers for that teaching, and to support pregnant pupils. The official English text is published by the Ministry of Labour. That is a national school sexuality-education duty.