19 CFR 201.205: Salary adjustments.

Any negative adjustment to pay arising out of an employee's election of coverage, or a change in coverage, under a Federal benefits program requiring periodic deductions from pay shall not be considered collection of a “debt” for the purposes of this section if the amount to be recovered was accumulated over four pay periods or less. In such cases, the Commission need not comply with § 201.204, but it will provide a clear and concise statement in the employee's earnings statement advising the employee of the previous overpayment at the time the adjustment is made.