What the law allows
Full record
Thailand’s Medical Council set surgery ages.
The official ข้อบังคับแพทยสภา พ.ศ. 2565 (Medical Council ethics regulation on treatment to change sex, published in the Royal Gazette 23 November 2022) says a person receiving sex-reassignment surgery under that regulation must be 20, or 18 but not yet 20 with the consent of the person with parental authority.
Clinics and unregulated hormone use still exist in Thailand. The official rule is the Council’s surgery-age line.
Schools. The Act for Prevention and Solution of the Adolescent Pregnancy Problem B.E. 2559 Section 6 requires educational establishments to provide sexuality studies appropriate to age. The 12 October 2018 ministerial regulation (B.E. 2561) tells institutions the content must cover sexual development, relationships, sexual health, and social and cultural dimensions, emphasizing gender diversity and equality. The Basic Education Core Curriculum B.E. 2551 (OBEC) already put sex education in Health and Physical Education Strand 2.