This report provides improper payment estimates for fiscal year 2011 using a methodology for “aging” the 2005 bookend study. The methodology yields nationally representative estimates of the number of vendors that over- and undercharged and the amount of over- and undercharges across all WIC vendors.

This report provides improper payment estimates for FY 2010 using a methodology for “aging” the 2005 bookend study. The methodology yields nationally representative estimates of the number of vendors that over- and undercharged and the amount of over- and undercharges across all WIC vendors.

This report provides improper payments estimates for FY 2009 using a methodology for “aging” the 2005 bookend study. This updates previous reports providing estimates from 2005 to 2008.

About every 7 years, FNS performs a nationally representative study to examine the extent of error and abuse among food vendors authorized to accept WIC vouchers. The last bookend study was the 2005 WIC Vendor Management Study, which used fiscal year 2005 expenditure data to derive an estimate for 2004. Between bookend studies, there is a need to derive annual estimates of the level of improper payments for compliance with the Improper Payments Information Act of 2002. The purpose of the subsequent annual studies was to provide annual updates to the bookend studies using the developed aging methodology.