48 CFR 9904.406-40 - Fundamental requirement.
(a) A contractor shall use this fiscal year as his cost accounting period, except that:
(2) An annual period other than the fiscal year may, as provided in 9904.406-50(d), be used as the cost accounting period if its use is an established practice of the contractor.
(3) A transitional cost accounting period other than a year shall be used whenever a change of fiscal year occurs.
(4) Where a contractor's cost accounting period is different from the reporting period used for Federal income tax reporting purposes, the latter may be used for such reporting.
(b) A contractor shall follow consistent practices in his selection of the cost accounting period or periods in which any types of expense and any types of adjustment to expense (including prior-period adjustments) are accumulated and allocated.
(c) The same cost accounting period shall be used for accumulating costs in an indirect cost pool as for establishing its allocation base, except that the contracting parties may agree to use a different period for establishing an allocation base as provided in 9904.406-50(e).