41 C.F.R. § 105-57.008 – Amounts withheld.

(a) After receipt of the garnishment order issued under this part, the employer shall deduct from all disposable pay paid to the applicable debtor during each pay period the amount of garnishment described in paragraph (b) of this section. The employer may use the SF 329C (Wage Garnishment Worksheet) to calculate the amount to be deducted from the debtor's disposable pay.
(b) Subject to the provisions of paragraphs (c) and (d) of this section, the amount of garnishment will be the lesser of—
1. (1) The amount indicated on the garnishment order up to 15 percent of the debtor's disposable pay; or
2. (2) The amount set forth in 15 U.S.C. 1673(a)(2) (Restriction on Garnishment), which is the amount by which a debtor's disposable pay exceeds an amount equivalent to thirty times the minimum wage. See 29 CFR 870.10.
(c) When a debtor's pay is subject to withholding orders with priority, the following will apply:
1. (1) Unless otherwise provided by Federal law, withholding orders issued under this part will be paid in the amounts set forth under paragraph (b) of this section and will have priority over other withholding orders which are served later in time. Notwithstanding the foregoing, withholding orders for family support will have priority over withholding orders issued under this part.
2. (2) If amounts are being withheld from a debtor's pay pursuant to a withholding order served on an employer before a withholding order issued pursuant to this part, or if a withholding order for family support is served on an employer at any time, the amounts withheld pursuant to the withholding order issued under this part will be the lesser of—
  1. (i) The amount calculated under paragraph (b) of this section; or
  2. (ii) An amount equal to 25 percent of the debtor's disposable pay less the amount(s) withheld under the withholding order(s) with priority.
3. (3) If a debtor owes more than one debt to GSA, the Agency may issue multiple withholding orders provided the total amount garnished from the debtor's pay for such orders does not exceed the amount set forth in paragraph (b) of this section.
(d) An amount greater than that set forth in paragraphs (b) and (c) of this section may be withheld upon the written consent of the debtor.
(e) The employer shall promptly pay to GSA all amounts withheld in accordance with the withholding order issued pursuant to this part.
(f) An employer will not be required to vary its normal pay and disbursement cycles in order to comply with the withholding order.
(g) Any assignment or allotment by an employee of his or her earnings will be void to the extent it interferes with or prohibits execution of the withholding order issued under this part, except for any assignment or allotment made pursuant to a family support judgment or order.
(h) The employer will withhold the appropriate amount from the debtor's wages for each pay period until the employer receives notification from GSA to discontinue wage withholding. The garnishment order will indicate a reasonable period of time within which the employer is required to commence wage withholding, usually the first payday after the employer receives the order. However, if the first payday is within ten (10) days after the receipt of the garnishment order, the employer may begin deductions on the second payday.
(i) Payments received through a wage garnishment order will be applied in the following order:
1. (1) To outstanding penalties.
2. (2) To administrative costs incurred by GSA to collect the debt.
3. (3) To interest accrued on the debt at the rate established by the terms of the obligation under which it arose or by applicable law.
4. (4) To outstanding principal.