It happened on September 21st when a contractor with the Maine Office of Information Technology was doing a system upgrade.
Officials said the contractor posted information from a Maine Department of Health and Human Services database to a third party website outside the State of Maine system.
The file consisted of information including the names, addresses and social security numbers of people receiving foster care benefits as well as the names of children and legal guardians participating in the program.
Officials said the information was removed as soon as they learned what had happened. A notice has been mailed out.
They are offering a year of credit and identity monitoring to those that have been affected.