The New York State Department of Health advised the struggling Peninsula Hospital in Queens on Tuesday to not admit any new patients until a new operational plan is in place.
DOH officials said their advice was given out of concern for patient safety because the hospital's financial problems were making it tough for it to meet minimum standards.
Ambulances were being diverted to other hospitals as well.
DOH officials also said that Peninsula must prepare a plan for the safe transfer for the remaining patients.
The measures were intended to go on until the hospital submitted a plan that adequately addresses safety and operational issues, according to the DOH.
According to a Peninsula board member, the head of the hospital ordered Tuesday morning that patients be discharged or sent to other hospitals, but said no patients had been moved.
Health officials were trying to figure out Tuesday whether the struggling hospital could be saved or should be closed.
The hospital board was making sure everything in the hospital is safe, according to the board member.
Hundreds of residents rallied Monday night in an effort to save the hospital.
If Peninsula closes, it would be the fourth hospital in Queens to shut its doors since 2008 and leave the Rockaways with just one hospital.