Health: other; gender reassignment procedures or treatment for minors; prohibit. Amends 1978 PA 368 (MCL 333.1101 - 333.25211) by adding secs. 17019 & 17519.

HB 4190 prohibits physicians in Michigan from performing gender reassignment surgery on minors or prescribing cross-sex hormones or puberty-blocking drugs with the intent of assisting gender transition. The bill directly affects minors under 18 seeking gender-affirming medical care, including hormone therapy or puberty suppression. Exceptions apply only to minors already receiving such treatment before the law's effective date, if the physician documented that stopping treatment would cause harm. The law defines key terms like "gender reassignment surgery" (including genital and non-genital procedures) and "puberty-blocking drugs" to clarify the scope of the prohibition.