Individual states have different methods for determining child support amounts. What is considered “income” and what “deductions” are taken from that income prior to support being calculated can vary greatly from one jurisdiction to the next. Generally speaking, there are three basic formulas currently in use:
Thirty-eight states, Guam and the Virgin Islands use the “Income Shares Model.” This approach seeks to insure that the child or children receive the same amount of income they would get if their parents were still together and pooling their resources. Accordingly, the court arrives at a child support amount based on the individual incomes of both the custodial and noncustodial parent, taking into account an economic table that determines the expected cost of child rearing.
The “Percentage of Income Model” bases child support only on the noncustodial parent’s income. A minority of states, including Alaska and Texas, use this model. There are two variations on this model: the “Flat Percentage Model” and the “Varying Percentage Model.” In states using the “Flat Percentage Model,” the percentage of income marked for support stays the same whether the noncustodial parent’s income changes or not. The “Varying Percentage Model” results in an adjustment of the percentage of the income as a person’s income increases or decreases.
The third basic child support calculation is known as the “The Melson Formula,” which is a more complex variation on the Income Shares Model that incorporates a number of public policy judgments with an eye on making sure the parents’ basic necessities are met as well as their child’s. For example, under the “Melson Formula” there is actually a standard of living adjustment for the child. This model is used in just three states: Montana, Delaware and Hawaii.
Above and beyond the mere calculation of a support obligation, under all three models courts are usually empowered to make equitable adjustments, which deviate from the calculated obligation in certain circumstances, such as cases involving a parent who is legally obligated to support other children, special needs or extraordinary expenses of the child (e.g., private school tuition, extraordinary medical care, etc.), and where one parent must travel great distance to exercise visitation. Perhaps the most frequently litigated issue is over how much to deviate from a child support calculation where a child is splitting their time equally between the parents’ homes (a.k.a. the “overnight residential credit”).
Child support calculations and any applicable credits or equitable adjustments can vary from state to state so it is important to consult with legal counsel who is licensed to practice in the jurisdiction where the child support is to be determined.