44 C.F.R. § 295.33
A Claimant may amend the Notice of Loss to include additional claims at any time before signing a Proof of Loss. After the Claimant has submitted a Proof of Loss and before submission of the Release and Certification Form, a Claimant may request that the Director of OCGFC consider one or more Losses not addressed in the Proof of Loss. The request must be submitted in writing to the Director of OCGFC and received not later than the deadline for filing an Administrative Appeal under § 295.32 or August 28, 2002, whichever is earlier. It must be supported by the Claimant's explanation of why the Loss was not previously reported. If good cause is found to consider the additional loss, the Director will determine whether compensation is due to the Claimant for the Loss under the Administrative Appeal procedures described in § 295.41 .
44 C.F.R. §295.33