(a) Assistance to an eligible person is granted by a social services official on the basis of an authorization prepared on the State-prescribed form. Such an authorization shall contain all pertinent information as to the status of the case and the amount of the authorized grants of assistance and shall be effective for a period of time coinciding with periods of eligibility determinations and redeterminations and shall be made not less frequently than:

1. (1) by the end of the third calendar month of the acceptance of an application for all new and reopened cases under the programs of Aid to Dependent Children and Aid to Dependent Children with an unemployed parent (ADC and ADC-U), as well as all Home Relief (including singles);
2. (2) by the sixth month after such certification for ADC and HR cases;
3. (3) every three months for ADC-U cases; and
4. (4) as needed in excess of the minimum where there is a predictable change in need or circumstances.