Is this just a "fired and rehired" scheme?

No. Workers are not fired by the client business and rehired by the PEO. Instead, a worker becomes an employee of two employers in a co-employment relationship. The PEO assumes employer responsibilities and liabilities for the human resource and personnel obligations of the worksite employees. This responsibility includes the employees wages and employment taxes, workers’ compensation and unemployment insurance, and employee benefits. The small business retains employer responsibilities and supervision for the production of the products or the delivery of services.