In a brief order, a three-judge panel of the U.S. 9th Circuit Court of Appeals agreed to a block the law, scheduled to take effect Jan. 1, pending a decision on its constitutionality.
The law would subject psychologists, psychiatrists and other mental health professionals to discipline by their licensing boards for providing minors therapy to change their sexual orientation.
The state says the therapy is ineffective and dangerous.
Therapists, minors and their parents, represented by a Christian-rights group, sued the state on the grounds the new law violates free speech rights.
A district court judge refused to block the ban, and the law’s opponents appealed to the 9th Circuit.
The three-judge panel has scheduled a briefing over the next several weeks but has not indicated when it might rule.