FORT WAYNE, Ind. — An Indiana medical software company has reported the private information of 3.9 million people nationwide was exposed when its networks were hacked earlier this year, the U.S. Department of Health and Human Services said Monday.

Medical Informatics Engineering reported the number of people affected by the hack to the federal agency on July 23. The Fort Wayne company announced June 10 that the attack on its main network and its NoMoreClipboard network began May 7 and was detected May 26. The company said the exposed information includes names, addresses, birthdates, Social Security numbers and health records.

A notice posted on the company’s website said the hack affected patients of 11 health care providers. They include Texas-based Concentra, which operates three urgent care centers in Maine; Franciscan St. Francis Health Indianapolis; and Rochester Medical Group in the Detroit area. The hack also affected patients served by 44 hospitals and other radiology centers in Indiana, Ohio and Michigan, the notice said.