48 CFR §9904.403-20

1. (a)The purpose of this Cost Accounting Standard is to establish criteria for allocation of the expenses of a home office to the segments of the organization based on the beneficial or causal relationship between such expenses and the receiving segments. It provides for:
   1. (1)Identification of expenses for direct allocation to segments to the maximum extent practical;
   2. (2)Accumulation of significant nondirectly allocated expenses into logical and relatively homogeneous pools to be allocated on bases reflecting the relationship of the expenses to the segments concerned; and
   3. (3)Allocation of any remaining or residual home office expenses to all segments.
2. (b)This Standard does not cover the reallocation of a segment's share of home office expenses to contracts and other cost objectives.