If you are granted an advance of sick leave, you are usually responsible for either making the sick leave up through subsequent sick leave accruals or paying back the agency with cash or a paycheck deduction.
However, if you retire for disability, resign, or are separated because of disability, you are not required to pay back any sick leave advances. Also, no refund is required if you enter active military duty with a right of restoration.
Advanced sick leave may be paid back by using your annual leave, as long as its not to avoid a forfeiture of annual leave at the end of the leave year.
Compensatory time granted in lieu of overtime earned subsequent to the advance of sick leave may not be credited toward reducing the balance of advanced sick leave.