§ 10-11A-7 NMSA 1978

A member may designate a spouse or dependent child as a beneficiary. In the event a retirement annuitant dies, the surviving beneficiary shall receive an annuity equal to two-thirds of the retirement annuity being paid to the retirement annuitant at the time of death; provided that the annuity paid to a beneficiary spouse shall cease upon the surviving spouse's death and the annuity paid to a beneficiary dependent child shall cease upon the child reaching eighteen years of age or upon the child's death, whichever comes first.