CNN  — 

Twenty-six states have passed bans on gender-affirming health care for transgender children and teenagers, according to a CNN analysis of data from the Movement Advancement Project, a nonprofit think tank that advocates for LGBTQ rights. An estimated 40% of transgender youth ages 13 to 17 live in these states, according to MAP and The Williams Institute.

These laws will be in the spotlight as the US Supreme Court hears oral arguments on December 4 in a case that challenges Tennessee’s ban on transgender care for minors. Gender-affirming care includes medically necessary, evidence-based care that uses a multidisciplinary approach to help a person transition from their assigned gender — the one the person was designated at birth — to their affirmed gender, the gender by which one wants to be known.

The case could have wide-reaching implications for transgender youth living in states that have passed similar laws. After the first gender-affirming care ban for minors became law in 2021, a flurry of states passed similar measures.

Gender-affirming care was a particularly hot-button topic for lawmakers on both sides of the issue in 2023. While 19 states passed laws banning gender-affirming care for minors last year, 11 states and the District of Columbia passed “shield” laws protecting access to care. The bans varied in scope with some states making it a felony crime to provide certain gender-affirming care to minors, while others prohibited the use of public funds.

So far this year, Ohio, Wyoming, South Carolina and New Hampshire joined the list of states banning gender-affirming care for transgender youth. Maine and Rhode Island, on the other hand, passed laws protecting it.

Not all laws banning gender-affirming care are currently being enforced. A legal challenge in Arkansas has halted the state’s ban while a temporary block is in effect in Montana. New Hampshire’s ban on surgical care for minors will be enforced starting January 1, 2025 (though studies have shown gender-affirming surgeries on transgender minors are rare in the United States). While Arizona has a 2022 law on the books banning surgical care for transgender minors, Democratic Gov. Katie Hobbs signed an executive order in 2023 ensuring access to gender-affirming health care.