Texas became the largest state to ban gender-affirming care for minors on Friday after Gov. Greg Abbott (R) signed a bill into law.

The law, which will take effect on Sept. 1, will prohibit health care providers from prescribing hormones or puberty blockers to minors or performing surgeries to help with their gender transition. 

It includes an exception for youth currently receiving hormones or puberty blockers and those that have attended 12 or more sessions of mental health counseling over a period of at least six months before they began treatment. But, it also requires that they be gradually taken off them “in a manner that is safe and medically appropriate.” 

Medical providers who are convicted of violating the law could have their license revoked. 

With Abbott’s signature, Texas joins 18 other states that have banned medication and surgical gender-affirming care for transgender minors, according to the Movement Advancement Project, which tracks state laws affecting the LGBTQ community. Arizona bans gender-affirming surgery but not medication like hormones.

Republicans throughout the country have railed against the use of gender-affirming care for minors, especially in the past year, arguing that it could cause irreversible effects at an age when they are too young to decide. 

Medical associations have emphasized that the care is warranted for adults and children who are experiencing gender dysphoria. Advocates have also argued that the bans only harm transgender youth. 

The American Civil Liberties Union and other advocacy groups pledged last month to file a lawsuit if Abbott signed the bill to block the ban from going into effect.