When the board declares an additional earnings credit for a plan year, the board also may declare by plan amendment an additional annuity credit, for members and annuity beneficiaries who are receiving an annuity as of the date specified by the board pursuant to Section 25006, based on the balance of credits transferred from the member`s Defined Benefit Supplement account to the Annuitant Reserve. The additional annuity credit, if declared by the board, shall be paid in a lump sum. In addition to the considerations specified in Section 25006, prior to declaring an additional earnings credit, the board shall consider both of the following: (a) The amount required for the plan year to apply the additional earnings credit to the Defined Benefit Supplement accounts of members who are not receiving an annuity under the Defined Benefit Supplement Program for the plan year. (b) Any other obligations incurred by the plan with respect to the Defined Benefit Supplement Program.