20 C.F.R. § 404.508 : Employees' Benefits — SOCIAL SECURITY ADMINISTRATION — FEDERAL OLD-AGE, SURVIVORS AND DISABILITY INSURANCE (1950- ) — OVERPAYMENTS, UNDERPAYMENTS, WAIVER OF ADJUSTMENT OR RECOVERY OF OVERPAYMENTS, AND LIABILITY OF A CERTIFYING OFFICER — Defeat the purpose of Title II

(a) General. Defeat the purpose of title II, for purposes of this subpart, means defeat the purpose of benefits under this title, i.e. , to deprive a person of income required for ordinary and necessary living expenses. This depends upon whether the person has an income or financial resources sufficient for more than ordinary and necessary needs, or is dependent upon all of his current benefits for such needs. An individual's ordinary and necessary expenses include:
(1) Fixed living expenses, such as food and clothing, rent, mortgage payments, utilities, maintenance, insurance (e.g., life, accident, and health insurance including premiums for supplementary medical insurance benefits under title XVIII), taxes, installment payments, etc.;
(2) Medical, hospitalization, and other similar expenses;
(3) Expenses for the support of others for whom the individual is legally responsible; and
(4) Other miscellaneous expenses which may reasonably be considered as part of the individual's standard of living.
(b) When adjustment or recovery will defeat the purpose of title II. Adjustment or recovery will defeat the purposes of title II in (but is not limited to) situations where the person from whom recovery is sought needs substantially all of his current income (including social security monthly benefits) to meet current ordinary and necessary living expenses.

20 C.F.R. §404.508

32 FR 18026, 12/16/1967, as amended at 34 FR 14888, 9/27/1969