45 C.F.R. § 31.2
In this part, unless the context otherwise requires:
Administrative offset means withholding funds payable by the United States (including funds payable by the United States on behalf of a State government) to, or held by the United States for, a person to satisfy a claim.
Day means calendar day. For purposes of computation, the last day of the period will be included unless it is a Saturday, Sunday, or a Federal legal holiday, in which case the next business day will be considered the last day of the period.
Debt or claim means an amount of money, funds, or other property determined by an appropriate official to be owed to the United States from any individual, entity, organization, association, partnership, corporation, or State or local government or subdivision, except another Federal agency.
Debtor means an individual, organization, association, partnership, corporation, or State or local government or subdivision indebted to the Government, or the person or entity with legal responsibility for assuming the debtor's obligation.
Department means the Department of Health and Human Services, and each of its Operating Divisions and regional offices.
Evidence of service means information retained by the Department indicating the nature of the document to which it pertains, the date of mailing of the document, and the address and name of the debtor to whom it is being sent. A copy of the dated and signed written notice of intent to offset provided to the debtor pursuant to this part may be considered evidence of service for purposes of this regulation. Evidence of service may be retained electronically so long as the manner of retention is sufficient for evidentiary purposes.
FMS means the Financial Management Service, a bureau within the Department of the Treasury.
IRS means the Internal Revenue Service, a bureau of the Department of the Treasury.
Legally enforceable means that there has been a final agency determination that the debt, in the amount stated, is due and there are no legal bars to collection action.
Operating division means each separate component, within the Department of Health and Human Services, including, but not limited to, the Administration for Children and Families, Administration on Aging, the Centers for Disease Control and Prevention, the Centers for Medicare & Medicaid Services, the Food and Drug Administration, the National Institutes of Health, and the Office of the Secretary.
Past-due debt means a debt which the debtor does not pay or otherwise resolve by the date specified in the initial demand for payment, or in an applicable written repayment agreement or other instrument, including a post-delinquency repayment agreement.
Secretary means the Secretary of the Department of Health and Human Services, or the Secretary's designee within any Operating Division or Regional Office.
Taxpayer identifying number means the identifying number described under section 6109 of the Internal Revenue Code of 1986 (26 U.S.C. 6109 ). For an individual, the taxpayer identifying number is the individual's social security number.
Tax refund offset means withholding or reducing a tax refund payment by an amount necessary to satisfy a debt owed to the United States by the payee(s) of a tax refund payment.
Tax refund payment means any overpayment of Federal taxes to be refunded to the person making the overpayment after the IRS makes the appropriate credits as provided in 26 U.S.C. 6402 for any liabilities for any tax on the part of the person who made the overpayment.
45 C.F.R. §31.2