48 CFR 33.206: 33.206 Initiation of a claim.

(a) Contractor claims shall be submitted, in writing, to the contracting officer for a decision within 6 years after accrual of a claim, unless the contracting parties agreed to a shorter time period. This 6-year time period does not apply to contracts awarded prior to October 1, 1995. The contracting officer shall document the contract file with evidence of the date of receipt of any submission from the contractor deemed to be a claim by the contracting officer.

(b) The contracting officer shall issue a written decision on any Government claim initiated against a contractor within 6 years after accrual of the claim, unless the contracting parties agreed to a shorter time period. The 6-year period shall not apply to contracts awarded prior to October 1, 1995, or to a Government claim based on a contractor claim involving fraud.