The Supreme Court on Thursday limited the government's ability to strip U.S. citizenship from immigrants for lying during the naturalization process.
The justices ruled unanimously in favor of an ethnic Serb from Bosnia who lied about her husband's military service.
Justice Elena Kagan wrote for the court that false statements can lead to the revocation of citizenship only if they "played some role in her naturalization."
The court rejected the position taken by the Trump administration that even minor lies can lead to loss of citizenship.
The woman, Divna Maslenjak, and her family were granted refugee status in 1999 and settled near Akron, Ohio, in 2000. She became a citizen in 2007.
She initially told immigration officials her husband had not served in the Bosnian Serb military. That was a lie, she later conceded, and lower courts upheld a criminal conviction against her. The conviction automatically revoked her citizenship, and she and her husband were deported in October.