The SSA-8106/SSA-8106A should be used to compute payments when the system is unable
            to do so. This may occur, for example, when data input into the system is incompatible
            or incomplete and it becomes necessary to perform a manual computation. When the SSA-8l06/SSA-8l06A
            is used to manually compute a retroactive or ongoing payment amount, the form should
            become part of the claimant's file. When deeming is a factor and a deeming worksheet
            (SSA-8015, or SSA-8016) has been used to compute benefits, the use of the SSA-8106/SSA-8016A
            is optional.
         
         The form may also be used to provide an individual with an estimate of the amount
            payable to him as well as to explain the factors used to estimate payments, it should
            be annotated “payment estimate." The "payment estimate" need not be retained.