Aetna officials say paper files containing personal information for about 4,900 of its enrollees in New Jersey and Pennsylvania were thrown out as part of an office move in Blue Bell, Pa.

The files, containing the Social Security Numbers and birth dates for members of the Hartford, Conn.-based health plan, were left in a file cabinet that the company discarded, the company said in a statement.

When discovered, all of the files were returned, according to Aetna officials, who said they have no reason to believe the information has been or will be used improperly.

Affected members were notified and have been offered free credit monitoring services, the company said.

Most of the documents in the file cabinet were health plan dependent enrollment forms from the 2003 to 2007 period for people who worked for mid-sized employers and lived in New Jersey or Pennsylvania, officials said. About a dozen subscribers’ explanation-of-benefit forms also were returned with the files.