The Claims Manual
Purpose The purpose of the NFIP Claims Manual is to improve clarity of claims guidance to WYOs, vendors, adjusters, and examiners so that policyholders experience consistent and reliable service. The manual provides processes for handling claims from the notice of loss to final payment. All NFIP bulletins, other than those announcing Flood Insurance Claims Office numbers, Flood Response Office locations, claims adjuster briefings, and current and future program changes, are superseded by this manual and of no further effect.
Source: The above is from the Claims Manual
Please note that there is the NFIP Claims Manual and a NFIP Insurance Manual. The Insurance Manual is available on the same page as the Claims Manual but "is used primarily by insurers and agents selling and servicing NFIP flood insurance."