20 CFR § 422.440 - What are your employer's responsibilities under an administrative wage garnishment order?
(a) When withholding must begin. Your employer must withhold the appropriate amount from your disposable pay on each payday beginning on the first payday after receiving the garnishment order issued under this section. If the first payday is within 10 days after your employer receives the order, then your employer must begin withholding on the first or second payday after your employer receives the order. Withholding must continue until we notify your employer to stop withholding.
(c) Other assignments or allotments of pay. Your employer cannot honor an assignment or allotment of your pay to the extent that it would interfere with or prevent withholding under this section, unless the assignment or allotment is made under a family support judgement or order.
(e) When withholding ends. When we have fully recovered the amounts you owe, including interest, penalties, and administrative costs that we charge you as allowed by law, we will tell your employer to stop withholding from your disposable pay. As an added precaution, we will review our debtors' accounts at least annually to ensure that withholding has been terminated for accounts paid in full.
(f) Certain actions by an employer against you are prohibited. Federal law prohibits an employer from using a garnishment order issued under this section as the basis for discharging you from employment, refusing to employ you, or taking disciplinary action against you. If your employer violates this prohibition, you may file a civil action against your employer in a Federal or State court of competent jurisdiction.