The suit alleges that the company mismanaged, corporately looted, and neglected the Delaware County-based Crozer Health System for years.
It went on to allege that these circumstances led to a hospital closing and cuts to services at other facilities.
"They guaranteed no hospital would close, that there would be no substantial cuts to services for at least a decade," noted Attorney General Michelle Henry.
Doctors within the healthcare system told Action News that times have been tough.
"Chronic understaffing, a critical shortage of necessary supplies," explained Dr. Monica Taylor.
The lawsuit also alleges that Prospect Medical had broken the initial purchase agreement, which was approved by a court back in 2016.
"Prospect signed an agreement, they are on record telling the community they fully intended to maintain Crozer as a robust network. 'We're an expansion company, not a contraction company,'" Henry explained.
The complaint filed by the attorney general would hold Prospect Medical accountable and keep full services available, authorities say.
"Our legal action shows how corporate greed has severely harmed Delaware County's largest health care provider -- its patients, its staff, and its community," said Henry.
Officials say the lawsuit also seeks a preliminary injunction to preserve remaining services and the appointment of a receiver to manage the system for the immediate future.
Pennsylvania Senator Tim Kearney says he is supporting the lawsuit.
"The days of putting profits over patient care are numbered," he said. "Prospect has had eight long years to do the right thing -- make the necessary infrastructure investments, pay their bills, and treat their employees with respect."
Maureen May is a registered nurse at Temple University Hospital and the president of the Pennsylvania Association of Staff Nurses and Allied Professionals (PASNAP).
She says news of the lawsuit brought hope to a broken health system.
"They've taken not only the care away from the communities there, they pushed it out to other communities and overwhelmed other health systems as well," May said.
"Just look at their website, they're a highly reliable organization and tout patient safety. They're far from that when you're looking at that community in Delco. They've removed reliability and integrity," she added.
In a statement, Prospect Medical called the lawsuit "hasty and ill-considered."
Prospect also went on to say that the lawsuit will only harm Crozer Health and reduce access for patients in the community.
Meanwhile, healthcare workers say they're hoping for a quick transition, as they are desperate for proper care and resources.