In a news release issued Wednesday, the company said it plans to close the hospital at Broad and Vine streets on or about September 6th.
Philadelphia Academic Health System, LLC (PAHS), said the closing is due to continuing, unsustainable financial losses.
Hospital management met with staff nurses in the morning to deliver the news.
Hahnemann had already laid off 175 workers in early April, citing a multi-million dollar deficit, which was increasing each month by $3 to 5 million.
The April layoffs included 66 nurses, 22 technical workers, and 88 non-union employees.
In Wednesday's statement, Joel Freedman, the founder and president of PAHS, said, "We relentlessly pursued numerous strategic options to keep Hahnemann in operation, and have been uncompromising in our commitment to our staff, patients, and community. We are saddened our efforts have not been successful."
The hospital said it is working with city and state officials to begin closing down its inpatient and outpatient services.
PASNAP, the union representing 800 registered nurses at Hahnemann, has appealed to Mayor Jim Kenney, Philadelphia City Council, the Pennsylvania Legislative Delegation, and Governor Tom Wolf to intervene in a bid to keep the hospital open.
The union has asked that the property "not be used as a real estate commodity to enrich its current owner."
Hahnemann University Hospital has 496 beds and about 2,500 workers.
The long, recently turbulent history of Hahnemann University Hospital.
American Academic Health System, the parent company of PAHS, is a California-based for-profit corporation.
The Hospital and Healthsystem Association of Pennsylvania is also keeping its eye on the Hahnemann situation.
"Patient care is paramount. HAP is working with key stakeholders to ensure that patient access to care is not disrupted," said HAP president and CEO Andy Carter.
Philadelphia Academic Health System, LLC, also owns St. Christopher's Hospital for Children.
But Freedman said it is not in danger of closing.
"While Hahnemann will be closing, I want to be clear that St. Christopher's will remain open. This difficult choice will enable us to focus on the future of St. Christopher's," Freedman said in the statement. "We anticipate a bright future for the hospital and its uniquely talented team."