Bellevue Hospital in Manhattan is now offering walk-in, non-emergency services 24 a day.
It's a step forward in efforts to recover from Superstorm Sandy.
Bellevue also will offer limited adult and pediatric outpatient primary care clinics, and routine OB-GYN services.
Limited emergency care services are expected by mid-December.
The hospital says it will resume full operations in February.
The National Guard aided Bellevue's efforts to stay open by hauling fuel to Bellevue's backup generators. But it was determined that flood damage would make it impossible to adequately power the hospital.
The fuel feed to the generators stopped working when an estimated 17 million gallons of water rushed into the hospital's 1-million-square-foot basement. The floodwaters also knocked out power to the hospital's elevators.