The ruling overturns a lower court decision that kept both women's names off of a birth certificate. The high court also agreed to hear the case of a Christian baker who refused to make a wedding cake for a gay couple.
The US Supreme Court ruled Monday in favor of a lesbian couple from Arkansas in a dispute over whose names should go on a baby's birth certificate.
The high court decision overturned an Arkansas Supreme Court ruling, which supported local officials' refusal to list both same-sex spouses on the official document.
The Supreme Court's ruling helps clarify the scope of protections provided by the court's landmark ruling in 2015 that legalized gay marriage.
Under the law, married lesbian couples had to get a court order to have both spouses listed as parents on their children's birth certificates.
The lower court had said state officials don't have to list both same-sex partners as named parents on birth certificates, although state law allows a birth mother's husband to be listed when the child is not biologically his.
The high court's most conservative justices - Clarence Thomas, Samuel Alito and Neil Gorsuch - dissented, saying the lower court's decision should have been upheld.
Baking a cake
Meanwhile the Supreme Court also agreed to hear the case of a baker who refused on religious grounds to make a wedding cake for a gay couple.
The court will hear an appeal by baker Jack Phillips of Colorado. A state court ruled that Phillips violated the state's anti-discrimination law when his Masterpiece Cakeshop, just outside of Denver, refused to make a wedding cake for a gay couple.
Several similar cases across the US are being pressed by Christian conservatives who oppose gay marriage, and argue that providing certain services to same-sex couples violates their religious beliefs.
The case will be argued at the start of the court's next term in October.
The legal dispute goes back to 2012 - when Colorado allowed same-sex civil union but not gay marriage.
Phillips told a gay couple, David Mullins and Charlie Craig, that due to his Christian beliefs, his store's policy was to deny service to customers wanting to purchase cakes to for same-sex weddings.
The two men from Colorado flew to Massachusetts to get married but then returned home to celebrate their vows with friends in Colorado.
Colorado's Civil Rights Commission found Phillips guilty of violating the state law and ordered him to take remedial steps including staff training and the filing of quarterly compliance reports.
In August 2015, Colorado's Court of Appeals ruled against Phillips and the state's Supreme Court subsequently refused to hear the case, prompting Phillips to appeal to the US Supreme Court.
"This has always been about more than a cake," Mullins said on Monday. "Businesses should not be allowed to violate the law and discriminate against us because of who we are and who we love."
bik/rc (AP, Reuters)