Concealed earnings represent the largest source of fraud in the U.S. unemployment insurance system. Individuals with relatively low earnings constitute a larger fraction of those committing such fraud. High-earnings individuals, however, account for larger dollar amounts of this fraud.

In the U.S. unemployment insurance program, most of the overpayments due to fraud arise from individuals collecting benefits while they are gainfully employed. In addition, the overpayments are dwarfed by payments unclaimed by some who are eligible for unemployment benefits.