A major increase in New York City subway service will be phased in over the summer with money appropriated in the new state budget, a senior MTA official said Tuesday.

More trains will run over a dozen lines — and the state budget will allow NYC Transit to hire more train operators, the official said.

The J, G and M lines are expected to get additional weekend trains in July, dropping wait times below 10 minutes, the said the official.

By August, weekend No. 1 and No. 6 trains should run close to every six minutes, and midday service on the C, N and R lines will be increased during the week.

By December, the G train will see additional midday service on weekdays, and more trains are scheduled to be added to the C, N and R lines on weekday evenings.

The plan has the J and M as well as the B and D lines receiving additional weekday trains by the summer of 2024

The extra trains are scheduled to arrive every eight minutes. The No. 3 and No. 5 lines are also expected to receive additional rolling stock next summer, bringing weekend wait times on those lines to 10 minutes.

The expansions depend on passage of the “conceptual agreement” on a state budget Gov. Hochul reached with lawmakers last week.

The exact amount earmarked for expanded subway service remains under negotiation, a Hochul spokesperson told the Daily News on Tuesday — but the MTA official said the agency expects $35 million in funding to run more trains.

Where possible, the official said, the MTA is trying to achieve the six-minute wait times called for by transit advocates. Some lines, however, are limited due to how closely together trains can run on the system’s century-old signalling infrastructure.

Those lines include the Lexington Avenue Nos. 4, 5 and 6 trains, which already run close to maximum frequency. It will also be hard to boost lines like the F and M, which merge near Rockefeller Center, or the N and Q, which merge near Times Square, the official said.

Transit advocates greeted the plans Tuesday.

Lisa Daglian, executive director of the Permanent Citizen’s Advisory Council to the MTA, called the service increases “hard fought and sorely needed.”

“The good news from this budget just keeps on coming,” she said. “We will be reaping the benefits for years to come.”

“It’s a very big deal for riders,” said Danny Pearlstein, spokesman for Riders Alliance, which spent the run-up to the budget lobbying for six-minute service on subways. “This is the biggest advance in service that we’ve seen in our lifetimes.”