50 CFR § 259.5 - Maximum deposit amounts and time to deposit.
(a) Other than the maximum annual ceilings established by the Act, the Secretary shall not establish an annual ceiling. However, deposits can no longer be made once a party has deposited 100 percent of the anticipated cost of all Schedule B objectives unless the Agreement is then amended to establish additional Schedule B objectives.
(b) Ordinarily, the Secretary shall permit deposits to accumulate prior to commencement of any given Schedule B objective for a maximum of ten years. However, at the Secretary's sole discretion and based on good and sufficient cause shown, the time period may be extended.