Ala. Code § 30-3-114
The order of retroactive support shall be a sum certain judgment and may cover all periods in which the non-supporting parent failed to provide support. For all time periods in which support is requested, the court shall consider the needs of the child or children and the ability of the parents to respond to these needs, and shall determine the amount of support due for each period by application of the child support guidelines found in Rule 32 of the Alabama Rules of Judicial Administration based upon the circumstances during the time period for which support is sought. If the judgment for retroactive support includes support due for a period of time in which aid was paid by the Department of Human Resources and an assignment of support rights thereby exists under Section 38-10-4 and Section 38-10-5, the department shall be entitled to recover any support due the department under Section 38-10-6.
Ala. Code § 30-3-114 (1975)