When Will Zohran Mamdani Be Sworn In as NYC Mayor?

Zohran Mamdani, a 34-year-old state assemblyman, won the New York City mayor’s race on Tuesday, beating his closest challenger, former Gov. Andrew M. Cuomo, by nearly 10 percentage points.

Here’s what will happen next as he officially takes office.

When will Mr. Mamdani be sworn in as mayor?

Mr. Mamdani’s term officially begins at 12:01 a.m. on Jan. 1, 2026, as dictated by the City Charter, New York’s governing document. He must, however, take an oath of office before commencing his duties as mayor, according to the State Constitution.

In the past, some mayors have opted to hold small swearing-in ceremonies just after midnight on New Year’s Day to ensure that the city is not momentarily without a leader. They’ve then held larger ceremonies for the public later in the day.

Former Mayor Bill de Blasio, the predecessor of the current mayor, Eric Adams, was sworn in at two minutes past midnight on Jan. 1, 2014, during a brief ceremony in the front yard of his house in Park Slope, Brooklyn. Later that day he was sworn in again, during a public inauguration in front of thousands at City Hall. Mr. de Blasio again took the oath on Jan. 1, 2018, after winning a second term the previous year.

Mr. Adams took the oath of office on Jan. 1, 2022, in a public ceremony in Times Square soon after the annual New Year’s Eve ball drop.

Mr. Mamdani has not publicly discussed plans for his swearing-in ceremony. A campaign spokeswoman declined on Thursday to comment on them.

What will happen at the swearing-in ceremony?

Mr. Mamdani will promise to uphold the U.S. Constitution, the New York State Constitution and the City Charter.

State law dictates who Mr. Mamdani may ask to administer his oath. He can choose an appeals court judge, the attorney general, an official from the City Clerk’s Office or any official authorized to notarize a legal document transferring property, such as a notary public.

By tradition, incoming mayors may choose to take their oaths of office while placing their hands on a copy of a religious text, such as the Bible or the Quran. (Mr. de Blasio took the oath using a Bible once owned by President Franklin D. Roosevelt.) A public official, however, is not required by law to take the oath using any text at all.

Mr. Mamdani will be required to file a written copy of his oath with the City Clerk’s Office. He must pay a $9 filing fee to do so.

What can Mr. Mamdani do before his inauguration?

Mayors-elect cannot take any official actions before being sworn in, but they can take steps to shape their administrations. Since the election, Mr. Mamdani has named members to his transition team, and late last month he said he planned to ask the current police commissioner, Jessica Tisch, to remain in her post when he takes office.