Governor Jim Doyle ordered all state agencies to review their procedures for protecting personal information.
It comes after social security numbers were mailed out to the public for the second time in more than a year.
EDS Corporation of Texas sent the mailings late last week to 260,000 Wisconsinites.
The informational brochures included the recipients' social security number on the address label.
EDS says the problem has since been fixed.
It says letters will go out to those affected next week with a new number for a special hot line related to the issue.