The MTA is dialing it in.

Cell phone service will be installed in all underground subway stations by Monday, Jan. 9, Gov. Andrew Cuomo announced Thursday.

Straphangers will be able to make calls through the four major carriers — Verizon, Sprint, T-Mobile and AT&T.

“By bringing Wi-Fi and cell service underground ahead of schedule, we are reimagining our subway stations to meet the needs of the next generation,” Cuomo said in a statement. “This will better connect New Yorkers who are on-the-go and build on our vision to reimagine the country’s busiest transportation network for the future.”

Transit Wireless, the company contracted with the agency to provide cell service and Wi-Fi throughout the system, spent more than $300 million on the project. It shares revenues derived through the network’s services with the MTA.

All but one underground station has cell service, according to officials. The last station, Clark Street of the 2 and 3 line in Brooklyn, will go live Monday.

“As of Monday, our customers can text or call from our underground stations, staying in touch with their families, keeping up with work, and staying connected,” said New York City Transit President Ronnie Hakim in a statement.

There are a few exceptions. Four stations either undergoing or about to undergo rehabilitation work will have to wait until those projects are complete before they’re connected: the South Ferry, Prospect Ave., 53rd Street and Bay Ridge stations.