A stolen computer has exposed the personal information — including names, social security numbers and addresses — of more than 650,000 Oregonians.

Thieves stole a computer from the troubled medical transportation company GridWorks last November. It had personal information of patients as well as the company identity numbers of the Portland-area Medicaid provider Health Share of Oregon.

Health Share issued a statement saying it didn’t know about the theft until GridWorks informed it in January. It said it immediately took steps to notify regulatory authorities and establish a system to for help.

“Though the theft took place at an external vendor, we take our members’ privacy and security very seriously. We are ensuring that members, partners, regulators, and the community are made fully aware of this issue,” CEO Maggie Bennington-Davis said in the statement.

“We are committed to providing the highest quality service to our members, which includes protecting their personal information,” she continued.

Health Share said it has not received any indication that the information has been accessed, but it’s now writing to members to inform them of the breach and offer a year of free identity monitoring.

Companies that do business with Health Share include CareOregon, Central City Concern, Adventist, Kaiser, Legacy, OHSU, Providence and Tuality. Health Share also contracts care with Clackamas, Multnomah and Washington Counties.