State officials announced in May that hackers broke into a government server and stole the personal information of about 780,000 people, including the Social Security numbers of about 280,000.
Utah's chief technology officer resigned in the wake of the theft.
The agency says those whose Social Security numbers were stolen now have until Sept. 30 to register for free credit monitoring. Health department officials say only about 20 percent of victims have so far enrolled for the service.
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