(a) A monthly annuity payable to a retiree or beneficiary is payable to that person through the month in which the person dies. A continuation of an optional annuity or the payment of a death or survivor benefit annuity begins with payment for the month following the month in which the death occurs.
(b) The effective date of death of a member who dies before retirement is, for the purpose of a death or survivor benefit annuity, the last day of the month preceding the month in which the member dies. The first payment of the annuity becomes due at the end of the month in which the member's death occurs.