45 CFR 233.35: Computing the assistance payment under retrospective budgeting after the initial one or two months (AFDC).

The State plan for AFDC shall provide:

(a) After the initial one or two payment months of assistance under § 233.34, the amount of each subsequent month's payment shall be computed retrospectively, i.e., shall be based on income and other relevant circumstances in the corresponding budget month except as provided in § 233.20(a)(3)(iii). In any month for which an individual will be determined eligible prospectively and will be added to an existing AFDC assistance unit, the State must meet the individual's needs to the same extent it would if the individual were an applicant for AFDC.

(b) Except as provided in § 233.34(b), for the first and second payment month for which retrospective budgeting is used, the State shall not count income from the budget month already considered for any payment month determined prospectively which is not of a continuous nature.