[PCI DSS 1.x] 8.5.9 Change user passwords at least every 90 days

8.5.9 For a sample of system components, critical servers, and wireless access points, obtain and inspect system configuration settings to verify that user password parameters are set to require users to change passwords at least every 90 days

For Service Providers only, review internal processes and customer/user documentation to verify that customer passwords are required to change periodically and that customers are given guidance as to when, and under what circumstances, passwords must change