Managed Care of North America Dental, a dental benefits administrator that works with state Medicaid agencies and insurance companies, suffered a data breach.
Nearly 9 million people were affected by the breach, according to a report Managed Care filed with the Maine attorney general.
The company became aware of the breach March 6. Information that was taken includes patient contact information, Social Security numbers, driver's license numbers, health insurance information, dental care information, bills and insurance claims, according to a May 26 notice from Managed Care.
Managed Care is offering patients identity theft protection services for one year.
The computer system and information was accessed between Feb. 26 and March 7, the notice said.