42 CFR §455.504

As used in this subpart— Medicaid RAC program means a recovery audit contractor program administered by a State to identify overpayments and underpayments and recoup overpayments. Medicare RAC program means a recovery audit contractor program administered by CMS to identify underpayments and overpayments and recoup overpayments, established under the authority of section 1893(h) of the Act.