A Manhattan judge is pausing the city’s plan to place 250,000 retirees onto a new privatized version of Medicare in the fall, documents show.

A deadline was scheduled for Monday for seniors to opt out of the coverage.

The judge on Friday granted a petition from a group of retirees to temporarily block the move while their lawsuit against the city is pending in court.

The retirees argue the Adams administration would diminish care and violate city law by making them move to the new Medicare Advantage plan run by Aetna.

The city has maintained that the plan offers a lower deductible, a cap on out-of-pocket expenses and offers new benefits.

The City Council Common Sense Caucus released a statement saying that switching retirees to Medicare Advantage would cause “irreparable harm.”

“This is why we fought to prevent the administrative code from being changed and were compelled to file an amicus brief in support of this lawsuit,” the City Council Common Sense Caucus wrote in a statement. “We urge the administration and union leaders to get back to the negotiating table to find health insurance savings without diminishing the benefits our retirees have earned.”

Harry Nespoli, chairman of the Municipal Labor Committee, called the decision “disappointing.”

“But we will continue to work to ensure that high-quality, premium-free health care is available for city employees and retirees,” he wrote in a statement. “We understand that the city intends to file an appeal promptly.”