Texas Attorney General Ken Paxton sued Wednesday to stop the Biden administration from enforcing its “pharmacy mandate” requiring qualified retail pharmaceutical firms to dispense abortion pills or risk losing Medicare and Medicaid funding.

The lawsuit, filed Tuesday in U.S. District Court for the Western District of Texas, cited the Health and Human Services Department’s July 13 guidance saying that refusing to fill prescriptions for abortion pills would violate federal law banning sex discrimination based on pregnancy.

The guidance cited the Affordable Care Act and the 1964 Civil Rights Act, but Mr. Paxton argued that none of the federal statutes named addresses pregnancy, and that “the Defendants know this” because they issued a proposed rulemaking in August to add pregnancy discrimination to the ACA, popularly known as “Obamacare.”

On the other hand, he said that the administration’s “pharmacy mandate” runs afoul of the ACA, which includes a section saying that it does not preempt state law on abortion, as well as Title IX and the Hyde Amendment.

“The Biden Administration knows that it has no legal authority to institute this radical abortion agenda, so now it’s trying to intimidate every pharmacy in America by threatening to withhold federal funds,” Mr. Paxton said.

“It’s not going to work. Texas and several other states across the country have dutifully passed laws to protect the unborn, and we are not going to back down just because unelected bureaucrats in Washington want to create illegal, extremist federal policies,” he said.

The challenge comes as the Biden administration spars with red states over access to mifepristone and Mifeprex, the two-pill regimen approved for terminating pregnancies up to 10 weeks’ gestation, which has become the most popular abortion method despite pro-life concerns about its safety for pregnant women.