VSP performs two kinds of audits: quality control (QC) audits, and targeted audits. Every practice should expect a QC audit every few years. These are routine audits in which you are asked to send VSP about 10 patient records, and receive back a report assessing your compliance with VSP rules.
A "targeted audit" is performed by a special division of VSP called their SIU, or Special Investigations Unit. The SIU is made up of a small group of 4-5 trained fraud investigators. They regularly examine data to watch for billing patterns which suggest to them that you may be billing improperly or even commiting fraud.
For instance, billing a high volume of visually necessary contact lenses, having a high dispensing rate compared with other offices in your area, billing for a high volume of punctal plugs, and billing a high number of low-power prescriptions (+/- 0.50D) have all been recently known to trigger a "targeted audit." Anything you bill VSP for more than others in your area puts you on their "radar" and may trigger one of these audits.
In a targeted audit a VSP fraud investigator from the SIU will come into your office unannounced, and ask for anywhere from 30-50 charts, and will wait for you provide them. These charts are copied, and the auditor returns to his/her office and determines if you appear to be violating VSP rules. Targeted audits often lead to demands by VSP that you repay VSP $100,000 or more in "restitution," and/or removal from the VSP panel. Then, to add salt to the wound, VSP will begin withholding all VSP payments to you to pay down the restitution, even before you have a chance to appeal the audit findings.