Forensic Accountant

Irina Anissimova, CPA, CFF

Support Calculations

Child support is determined based on the statewide guideline formula described in California Family Code Section 4055. As a percentage of the paying parent’s income, child support payments may be in the range of 20% to 50%, depending on the number of supported children and both parents’ income.

Generally, child support payments stop when a child reaches 18 or finishes high school, whatever happens later (it can be 19 if the child is still at school at this time).


Child support amounts are established by a court order and their modification requires a change in circumstances and a court process. Change in circumstances is most often related to the changes in parents’ income, but may also include changes in their living arrangements and timeshare (for example, when one of the parents moves out of state).

When there are several children in the family, support payments will be reduced each time a child reaches the age of 18 (finishes high school) and this change alone generally does not require court proceedings.


The main factors that influence the amount of child support are both parents’ monthly net disposable income and the timeshare percentage of the non-custodial parent. Because determination of the net disposable income requires subtraction of applicable taxes, the calculation of child support becomes rather convoluted and is usually performed by a software application named Dissomaster.


A forensic accountant enters the picture when one or more of the following circumstances are present:

  • One or both parents have complex income streams where regular salary is not the most substantial part of the total income (for example, when a major part of the compensation is earned as bonuses, commissions, or equity in the employer’s company, or when there is substantial income from investments but no W-2 income).
  • One or both parents derive their income from a business.
  • The parent being ordered to pay child support has very high income and wants to argue that the amount determined under the formula would exceed the needs of the children.
  • There have been changes in the timeshare arrangements and/or income of one or both parents and there is a need to calculate child support payable under different circumstances for several different time periods after separation.
  • There have been offsets of expenses against the support obligation and/or support was not paid in full and there is a need to determine arrears.

Generally speaking, most of the work performed by an accountant with regards to child support is related to defining what income is available to pay it. 


Because child support is only a part of the financial issues that need to be resolved in a divorce, it is not unusual to prepare several calculations under different scenarios and assumptions. Such scenarios explore the impact of different living arrangements and variations in timeshare, and they can also involve imputation of income to one of the parents or assumptions related to future investment or business income.


Besides documents needed to determine income available for support, an accountant will ask for the documents related to the calculation of income taxes - health insurance premiums, retirement contributions, and itemized deductions (mortgage statement, property tax statement, etc.).


Spousal support (alimony) payable during divorce proceedings (i.e. “temporary support”) is also calculated using a formula which allocates to the supported spouse about 40% of net income of the paying spouse (after deducting child support payments).

The amount of alimony to be paid after the divorce is final is established with the goal of assisting the supported spouse in maintaining a standard of living close to the marital standard (MSOL), although this is not the only factor which is considered by the court. More often than not, the paying spouse does not have enough income to pay support at the MSOL level, so a calculation is prepared to determine what amount of spousal support should be paid in order for the supported party to receive 50% or 40% of the combined net spendable income.


Family Code Section 4320 establishes the goal that the supported party shall be self-supporting within a reasonable period of time. It is possible, therefore, that one of the sides will want to impute future income to the supported spouse based on a vocational evaluation report.

Spousal support calculations use the same documents as child support calculations, with the exception of a possible vocational evaluation report.


Copyright: Irina Anissimova, CPA, CFF, 2015