Back on July 21 on DataBreaches.net, I reported that Idaho Power was among those affected by the Mercer Health Plan lost tape incident. Their loss was not mentioned on this site as it was not clear what protected health information might be involved. It seems that it was the Idaho Power Group Health Plan that was affected, and they have notified HHS that they notified 5,500 members of the lost backup tape. From an FAQ posted to their web site on August 12, it seems that they were not notified of the breach until June 16. The tape was lost after being shipped by FedEx on March 26.
Interestingly, their FAQ indicates that the Mercer breach affected over 375,000 individuals, total.