48 CFR 31.205-49: 31.205-49 Goodwill.

Goodwill, an unidentifiable intangible asset, originates under the purchase method of accounting for a business combination when the price paid by the acquiring company exceeds the sum of the identifiable individual assets acquired less liabilities assumed, based upon their fair values. The excess is commonly referred to as goodwill. Goodwill may arise from the acquisition of a company as a whole or a portion thereof. Any costs for amortization, expensing, write-off, or write-down of goodwill (however represented) are unallowable.