Most states have child support guidelines in their statutes—often in the statutes collected in the state’s family code. These child support guidelines provide percentages and methods of calculating child support payments based on the number of children; the parents’ incomes and financial resources; the income and needs of the custodial parent; the needs of the children, including any special needs; and the standard of living for the children before the parents’ divorce or separation. The child support guidelines are just guidelines, and the court generally has discretion to order more or less child support based on the best interest of the children.

In Massachusetts, child support guidelines are established to ensure that both parents contribute to the financial support of their children in a fair and equitable manner. These guidelines take into account the number of children, the income and financial resources of both parents, the needs of the custodial parent, the needs of the children (including any special needs), and the standard of living the children would have enjoyed had the family remained intact. The Massachusetts Child Support Guidelines are used by the courts to calculate a parent's child support obligation and are presumed to be in the best interest of the child. However, the court has the discretion to deviate from these guidelines if it finds that the application of the guidelines would be unjust or inappropriate under the circumstances. Factors that may lead to deviation include extraordinary medical expenses, the child's own income, or other financial resources available to the child. The guidelines are reviewed and may be revised periodically to reflect changes in law or the cost of living.