“This case is a disaster for the rule of law and a grave disservice to women in Texas, who have a right to control their own bodies,” Justice

Sonia Sotomayor

wrote in dissent, joined by Justices

Stephen Breyer

and Elena Kagan.

“With today’s ruling, the lawsuit will continue in the appropriate venue, and the Texas Heartbeat Act will continue to save preborn lives,” Texas Right to Life, a leading antiabortion group in the state, wrote in a statement on its website.

The Texas law, known as S.B. 8, bans nearly all abortions after about the sixth week of pregnancy, a restriction at odds with current Supreme Court precedent allowing women to obtain abortions prior to fetal viability, which occurs at about 24 weeks.

“Texans have been without abortion access for almost five months now, and there is no end in sight because the Supreme Court has done nothing to stop this unconstitutional ban,” said

Nancy Northup,

president of the Center for Reproductive Rights, which represents challengers to SB 8. “Seven other states have already introduced copycat bans now that the court has let Texas get away with this ploy.”

The Texas attorney general’s office didn’t immediately respond to a request for comment.

When states have enacted straightforward abortion bans, providers have been able to obtain injunctions by suing officials responsible for enforcement. Texas lawmakers sought to avoid such challenges by leaving enforcement up to private parties, providing them awards of at least $10,000 for filing civil lawsuits against those who provide abortions or assist women in obtaining them.

In its December decision, the Supreme Court by a 5-4 vote blocked a full-scale challenge to SB 8, finding that court clerks who would process SB 8 lawsuits weren’t appropriate defendants. But by an 8-1 vote the court found that some licensing officials, such as the head of the state medical board, played a role in SB 8’s enforcement and therefore could be sued.

At the providers’ request, Justice

Neil Gorsuch

expedited return of the case to the appeals court. In turn, the Fifth Circuit, rather than sending the case back to federal district court for proceedings against the licensing officials, scheduled argument on Texas’ motion to refer to the state Supreme Court the question of whether the state licensing officials actually were involved in SB 8’s enforcement.

Providers then returned to the Supreme Court on Jan. 3 asking the justices to order the Fifth Circuit to immediately transfer the case back to the district court. The clinics said the Fifth Circuit was entertaining superfluous legal questions that already had been resolved by the Supreme Court, delaying their opportunity to restore abortion rights in Texas.

The U.S. Supreme Court took no action before the Fifth Circuit’s Jan. 7 hearing, and the appeals court later granted Texas’s request to send the issue to the state Supreme Court. That leaves SB 8 in effect at least until the Texas Supreme Court responds to the Fifth Circuit.

At a Jan. 7 hearing, at least one Fifth Circuit judge suggested that delay could be for the best: In a separate case from Mississippi, the U.S. Supreme Court is considering whether to reduce or eliminate the constitutional right to end unwanted pregnancies that it recognized in 1973 in Roe v. Wade.

“Maybe we should just sit on this until the end of June and leave the hot potato with the Supreme Court,” Judge Edith Jones said, referring to when the justices typically announce their most contentious decisions.

In a separate dissent joined by the other two liberals, Justice Stephen Breyer said the Fifth Circuit “ignored our judgment,” leaving “an unconstitutional 6-week abortion ban in effect in Texas—as it has for over four months.”

The Texas law, passed in May, bars doctors from knowingly performing an abortion if there is a “detectable fetal heartbeat,” defined to include early cardiac activity in the embryo. It contains no exceptions for rape or incest.

The Fifth Circuit blocked challenges to SB 8 before it took effect on Sept. 1; the U.S. Supreme Court, by a 5-4 vote, declined then to intercede.

In October, however, the high court agreed to consider whether providers could proceed with their challenge, with an expedited schedule that saw argument in November leading to last month’s decision.

The Supreme Court’s conservative majority and the Fifth Circuit have described the issues with the law as procedural rather than directly related to abortion.

Justice Sotomayor on Thursday called those assertions disingenuous. “The state legislature enacted a convoluted law that instills terror in those who assist women exercising their rights between 6 and 24 weeks,” she wrote.

Write to Jess Bravin at jess.bravin+1@wsj.com

Corrections & Amplifications
Justice

Samuel Alito

oversees the federal judiciary’s New Orleans-based Fifth Circuit. An earlier version of this article incorrectly said Justice Neal Gorsuch did so. (Corrected on Jan. 20.)