The majority of information on the computers was also protected by multiple passwords, the department said.
News of the theft was released only yesterday because officials first needed to determine what type of information was stored on the desktop computers and how many people could possibly have been affected.
Witalec said Capitol Police, the force that monitors the State Capitol buildings, is investigating the burglary.
The Public Welfare department has also started mailing letters to those who may have been affected to notify them of the theft and to assist them with any steps they will need to take if they suspect their identity may have been stolen.
"We have no evidence to show that any information has been used inappropriately," Witalec said yesterday.
According to Witalec, the Public Welfare Department's offices are locked in the evenings. A key is needed to access the building.
The department is not manned after hours, but the building is patrolled overnight by Capitol Police, said Ed Myslewicz, spokesman for the Department of General Services, which oversees the Capitol Police.
The Public Welfare Department's joint state/federal Medical Assistance program purchases health care for nearly 1.9 million Pennsylvania residents.
Based upon a person's eligibility category, covered services may include physician and clinic visits; inpatient hospital care; home health care; medical supplies and equipment; nursing facility care; inpatient and outpatient psychiatric and drug and alcohol services; prescription drugs; dental and other medically necessary services.
Public Welfare Secretary Estelle B. Richman said in a statement that "the department is taking all appropriate steps to prevent an incident like this from occurring in the future and is working with both state and local authorities and community partners to help those potentially affected," she added.
Contact staff writer Angela Couloumbis at 717-787-5934 or acouloumbis@phillynews.com.