New York City's first lady Chirlane McCray requested a deferment Thursday from jury duty in Brooklyn, where the de Blasios had lived until moving into Gracie Mansion last summer.
The first lady told the court that her duties may make it hard for her to serve in the Eastern District of New York courthouse until 2018, McCray's spokeswoman said Thursday.
A U.S. District Court official said that McCray did not have to serve in Brooklyn because she and her family now reside in Manhattan.
"She was excused from jury duty because her residence has changed, and she's no longer in our district," the court's district executive Eugene Corcoran said.
Mayor Bill de Blasio separately said his wife could serve this fall but first must help prepare the couple's children, Chiara, 19, and Dante, 17, for college.
"I think every citizen has a right to ask for a postponement, but they must serve," de Blasio said at an unrelated event in the South Bronx. "She's going to serve in October after she gets her children to college."
Chiara de Blasio this fall will be a senior at California's Santa Clara University. Her brother, Dante, will start his freshman year at Yale University.
McCray's spokeswoman, Erin White, later clarified that the first lady would be willing to serve as soon as October.
The de Blasios still vote in Brooklyn, where they lived for years in a Park Slope row house until they moved into the mayoral mansion on the Upper East Side.
The earliest McCray and her family would return to Brooklyn is January 2018, after de Blasio's first term ends. He has said he will run for re-election.
McCray, who is chair of the nonprofit Mayor's Fund to Advance New York City, is a key adviser to her husband's administration.
McCray is shaping mental health initiatives in the city, including NYC Safe, which aims to steer emotionally disturbed people and those prone to violence toward mental health services.