Fluctuating Income and Child Support – Family Code 4064

The guideline formula assumes a steady monthly income. Many parents do not have one. Drivers paid by the hour with heavy overtime in peak season, teachers paid on a ten-month schedule, salespeople on commission and the self-employed all have income that rises and falls through the year.

California Code Family Code § 4064 addresses this directly: the court may adjust the child support order as appropriate to accommodate seasonal or fluctuating income of either parent. In practice that usually means averaging income over a representative period, often twelve months, rather than taking the most recent pay stub at face value.

The choice of period matters. A parent whose income is rising will argue for the recent months; a parent whose income is falling will argue for a longer average. Peak-season overtime is the classic dispute: the parent who earned it argues it was a one-time surge, the other parent argues it recurs every year. Year-over-year tax returns and employer earnings histories usually settle the question.

If a parent’s income later changes substantially and durably, the remedy is a modification based on changed circumstances, not an argument about how the original average was computed.