Attorney General Ken Paxton is suing a North Texas doctor for allegedly providing gender-affirming care to nearly two dozen patients after the state’s ban took effect last September.

In the suit announced Wednesday, Paxton claims that Dr. May Lau, an adolescent medicine specialist at Children’s Medical Center Dallas and an associate professor at UT Southwestern, violated Senate Bill 14 by prescribing testosterone to 21 patients after the law took effect Sept. 1, 2023.

The 35-page suit accuses Lau of writing prescriptions prior to Sept. 1 "with orders to fill prescriptions after SB 14 took effect." It also alleges she falsely billed insurance for another patient to obscure a prescription for a "puberty blocker device."

The lawsuit refers to Lau as a "scofflaw" and "radical gender activist," and maintains that each violation is a separate ground for the revocation of her license.

Asked for comment, a Children’s Health spokesperson said the hospital system adheres to state health care laws and directed the request to UT Southwestern.

Neither Lau nor UT Southwestern immediately responded to KERA News’ request for comment.

Paxton said the state will continue to prosecute doctors who continue to provide “harmful ‘gender transition’ drugs and treatment.”

“Texas passed a law to protect children from these dangerous unscientific medical interventions that have irreversible and damaging effects,” Paxton wrote in a statement.

Numerous medical organizations, including the American Medical Association and American Academy of Pediatrics, have endorsed holistic gender-affirming care as treatment for children experiencing gender dysphoria, or distress experienced by people whose gender is not the same as their sex assigned at birth.

Lau was associated with the now-defunct GENECIS clinic. Offered through a partnership between Children’s Medical Center Dallas and UT Southwestern, GENECIS was one of the only clinics in the Southwest to provide holistic gender-affirming care.

Founder Dr. Ximena Lopez closed the clinic in 2023 amid growing hostility towards transgender individuals – and as lawmakers prepared to pass SB 14.

SB 14 outlaws gender-affirming health care for children, which can include puberty blockers; therapy using hormones such as estrogen and testosterone; and surgeries.

The law also directs the Texas Medical Board to revoke the medical licenses of those who violate it.

Texas families of trans children and various organizations filed a lawsuit to prevent SB 14 from going into effect. A Travis County judge granted a temporary injunction, but the state’s swift appeal to the state Supreme Court overturned the ruling. The court in June upheld the law.

Paxton has also kept pressure on medical providers, including some out-of-state. In the last year, Paxton demanded medical records of Texas children who received gender-affirming care from Georgia-based telehealth clinic QueerMed and Seattle Children’s Hospital.

A hospital administrator denied clinic staff provided care to Texas children in the state or remotely from Washington, but the hospital agreed to stop doing business in Texas altogether, according to an April 22 press release. The agreement came after Seattle Children’s sued the state attorney general’s office to fight the subpoena.

Got a tip? Email Kailey Broussard at kbroussard@kera.org.