Nearly 15,000 nurses are walking off the job at hospitals across Manhattan and the Bronx on Monday morning after contract talks with hospitals faltered over the weekend.

The New York State Nurses Association, making good on strike threats announced weeks ago, said the first pickets would go up about 6 a.m. outside the affected medical centers, which are operated by Montefiore Medical Center, Mount Sinai Health System and NewYork-Presbyterian.

NYSNA President Nancy Hagans said ahead of the walk out that nurses preferred to continue providing patient care, “but our bosses have given nurses no other option but to strike.”

A spokesperson for Montefiore said on Sunday that he anticipated this strike could last weeks.

Dr. Brendan Carr, CEO of Mount Sinai Health System, shared a similarly bleak outlook in a memo to employees Sunday afternoon.

“The planning and personnel costs required to responsibly run our hospitals for what we anticipate could be a long strike are substantial, but we are prepared to maintain these operations,” Carr said.

The work stoppage, which the union said would be the largest by nurses in city history, comes as hospitals are anticipating significant financial losses as a result of federal cuts to Medicaid and other health care funding. The nurses’ prior agreements expired Dec. 31.

The last nurses’ strike in New York City was in 2023, after nurses had been hailed as heroes during the COVID-19 pandemic. It lasted three days before nurses won significant salary boosts and new staffing guarantees. This time around, nurses say they are fighting to protect those gains and address other issues like workplace violence.

Representatives of Mount Sinai, Montefiore and New York-Presbyterian say NYSNA’s proposed salary and benefit packages will drive up hospital costs by billions of dollars in the coming years as they face down these financial pressures.

But NYSNA leaders argued that less well-financed hospitals have already managed to settle negotiations with the union.

Mayor Zohran Mamdani said Sunday evening in a statement posted on X that he was “relieved that most hospitals have reached an agreement and urge the remaining parties to stay at the table and reach a deal that both honors our nurses and keeps our hospitals open.”

He added that the Office of Emergency Management, the Fire Department and the public hospital system were closely monitoring the situation and coordinating on contingency plans.

The Nurses Association said on Sunday they were still negotiating over wages with the three medical centers but were also prioritizing demands related to workplace safety, in light of recent violent incidents at hospitals, as well as health benefits and staffing standards.

Carr said in Sunday’s memo that the cost of hiring outside nurses and making other contingency plans for the strike was eating into Mount Sinai’s budget for meeting unionized nurses’ demands.

He added that, despite ongoing negotiations, “the list of items left to resolve is long.”

The Nurses Association has countered in recent days that hospitals could have used their budgets to meet the union’s demands ahead of the planned strike, rather than spending money on strike preparations.

Carr said in his memo that in addition to recruiting temporary workers, Mount Sinai has also been making other adjustments to prepare for the strike that could affect patient care. He said the health system has been working to identify patients who could be safely discharged, transferring patients between Mount Sinai facilities based on their capacity and rescheduling appointments and operations as needed.

Gov. Kathy Hochul issued an executive order Friday declaring a disaster emergency because of the strike that allows doctors and nurses from other states and Canada to practice in New York.

Hochul urged nurses and hospital management to work to reach an agreement to avoid a strike, which she said could put New Yorkers’ lives in jeopardy.

But on Sunday evening, the governor conceded that a strike was likely and said the state Department of Health would have staff onsite at all affected hospitals for the duration of the strike “to ensure patient safety and continuity of care.”

Ahead of the walkout, Hagans invited patients to join the nurses.

“Patients are welcome to join us [on the picket line] after they get taken care of,” Hagans said.

Here’s what else to know

Walk out at Mount Sinai locations were slated to start at 6 a.m. Monday and at hospitals operated by NewYork-Presbyterian and Montefiore Medical Center at 7 a.m.

Strike Locations:

Mount Sinai Hospital, Morningside and West;NewYork-Presbyterian’s Allen Hospital, Morgan Stanley Children’s Hospital and Columbia University Irving Medical Center;Montefiore Medical Center’s Jack D. Weiler Hospital, Henry and Lucy Moses campus, Hutchinson campus and the Children’s Hospital at Montefiore

The city’s Office of Emergency Management said ahead of the strike it would work with hospitals to coordinate patient transfers and reroute ambulances as needed.