After nearly a century in the making, the Second Avenue Subway will finally begin service on Jan. 1, officials said.

Gov. Cuomo announced on Sunday night that a ceremonial ride will take place on Dec. 31 before it opens to the public on New Years Day, according to NBC.

Construction on the Upper East Side subway — which will initially include three stops, connecting the Q train from 63rd St. to 96th St — first began in 2007. The project had been planned since 1929.

A second phase will eventually extend service up to 125th Street and is expected to cost between $4.5 billion and $5 billion.