5 CFR 1215.22 - Definitions.
(a) Claim or debt. An amount or property owed to the United States which includes, but is not limited to: Overpayments to program beneficiaries; overpayments to contractors and grantees, including overpayments arising from audit disallowances; excessive cash advances to grantees and contractors; and civil penalties and assessments. A debt is overdue or delinquent if it is not paid by the due date specified in the initial notice of the debt (see § 1215.26) or if the debtor fails to satisfy his or her obligation under a repayment agreement.
(b) Debtor. An individual, organization, group, association, partnership, or corporation indebted to the United States, or the person or entity with legal responsibility for assuming the debtor's obligation.
(c) MSPB. The Merit Systems Protection Board.