The Multiple Family Adjustment (MFA) in the Kansas Child Support Guidelines provides a reduction in child support payment in certain circumstances.
The MFA first appeared in the child support guidelines in 1990 as a single sentence. While the 2020 guidelines now provide a few paragraphs describing the MFA, the intent, use, and calculation of the adjustment remains the same.
The MFA method directs a non-residential parent to lookup the per-child child support amount from the table representing the total number of children that parent is legally obligated to provide for. Just FYI, the table I'm referring to is in the appendix of the guidelines. For example, if the Father has one child involved in the child support case, but remarries and has two additional children, the MFA adjustment method would allow Father to use the 3-child table, rather than the 1-child table to calculate child support, thereby reducing the child support award.
Per the child support committee meeting minutes, the MFA was created as a defense against a Mother filing for more child support. The reference to "sword and shield" was used. In this regard, the adjustment may not, itself, be deemed a change in material circumstances to justify an adjustment in child support. So, having a new baby, while a major change in the family dynamics and finances, may not actually be considered by the court a change in circumstances. Therefore, a noncustodial parent may not be able to request a change in child support due to such an event. In such a case, Father would need to wait until Mother requests a child support increase.
In my opinion, the way the MFA is applied to cases, to a degree, contradicts the underlying basis of the child support guidelines. The child support guidelines are designed to calculate the per-child child rearing cost. As the number of children in the family increases, it would be expcted that the per-child expenditures would decrease. And that principle is designed into the guidelines. However, the guidelines only consider children of the divorce. Other children are not considered part of the family. So, if there is one child of the divorce/separation, and the non-residential parent has 5 more children after the divorce, the child of the divorce is treated as an only child. In this case, the guidelines may not allow the MFA.