The period of availability to incur obligations in the Shipbuilding and Conversion, Navy (SCN) appropriation for all purposes is normally five years. For limited purposes, SCN funds are available for obligation after the five-year period has ended. Appropriation language for the SCN appropriation often contains a provision to the effect that additional obligations for engineering services, tests, evaluations, and other such budgeted work that must be performed in the final stage of ship construction may be incurred after the appropriation otherwise would expire for obligation. This additional period allowed for incurring new obligations for such purposes is called “extended availability.” DoD and Treasury employ special procedures to establish extended availability authority for the SCN appropriations because not all work required to induct a ship into the fleet can be completed within the first five years of availability of an SCN appropriation. The FY of the latest obligation work limiting date (OWLD) for the last vessel financed by a particular SCN appropriation must represent the period of availability for obligation. After such date, the appropriation enters an expired status for five years and the balances are available only for obligation adjustments and payments. An SCN appropriation is closed/cancelled on September 30 of the fifth year following the year of the last OWLD.