with their children.16 To our knowledge, only one other state, Tennessee, has adopted any formal method
of assessing increased child support in cases in which there is a court order or agreement for the non-
custodial parent to see the child little, or not at all.
For whatever reason—the amount of parent information necessary for calculating a child support
order in every California support case, or the complexity of the formula, or because of the possibility of a
lesser-time parent receiving child support at very low levels of time-share—no other state has adopted the
guideline used by California.
Below-Threshold Offset Formulas. The most common child support guideline used by states in
shared placement cases is some variation of the below-threshold offset formula, applied to a state’s sole-
custody guideline after reaching a defined threshold. There are several variations of this formula. Two
states, Nebraska and Wyoming, still use the simple version of this formula.17 It is of the form:
CS = [FAincome * BasicCS) * MOtime) - (MOincome * BasicCS) * FAtime]
Where: FAincome = father’s income MOincome = mother’s income FAtime = percent of child’s time with father, on an annual basis MOtime = percent of child’s time with mother, on an annual basis BasicCS = the basic amount of child support that would be owed in a sole custody situation, if that parent were the paying parent.
This formula uses the same basic elements as does California: mother’s and father’s income,
mother’s and father’s time with the child, and number of children. There are several important
First, the “basic” child support order levels in these states are much lower dollar amounts than the
initial amount (at zero time share) calculated by the California guideline. Basic child support guidelines,
used in sole custody cases, are generally one of three types, “Melson formula,” “income-shares model,”
16See Appendix Legal 4 for a discussion of a California court decision on this topic.
17This guideline was more popular in the past, and has been abandoned by several states in recent years (North Dakota and Virginia, for example).