Legal Question in Family Law in California

Not enough facts. Probably not. Support is based only partly on timeshare. The other main factor is the differences in incomes between the parties. The fact that you provide benefits (out of pocket? pretax?) should count something against your income available for support. Of course if your ex is the higher earner, maybe you'll be getting some child support. Joint custody, by the way, is really vague. I assume you mean an equal timeshare between the parents.

Child support is determined by a court approved computer program that runs an algorithm based on a complex formula in the Family Code. Whether or not you pay support depends on how the numbers crunch out. The formula, and therefore the program, starts with how much actual physical custodial or visitation time each parent has, and how much each parent makes. Then there is a lot of adjustments to the incomes that are similar to but not the same as tax deductions (payments for benefits such as medical insurance are one of the deductions), and then the program arrives at how much actual spendable income is attributed to each parent. The program then calculates how much of that income is assigned to supporting the children based on how many children there are. All this is in the Family Code formula, and the program calculates it. Then the program and the law assume that you spend that money on the children when they are with you, and assigns the money to the spouse when they are not. It then does the same thing with the spouse's income, assigning it to you when the kids are with you. Then the last step is to compare the assignments and order a payment to whomever is assigned more than they are assigned to pay. So, if you both make the same amount of money, and have exactly 50/50 time with the children, and you have the same deductions, but you are paying for benefits, you would get a small support payment. If you make twice what she does, but have the kids 2/3 of the time, it would still nearly zero out. If you make twice what she does and you have 50/50 custodial time, you would pay a substantial support payment. So the ultimate answer to your question is get a custody order that gives you enough custodial time to zero out any income difference. Unfortunately, since custody must by law be based on the best interests of the children, not on the fairness of any support order that results from the custody arrangement, getting a custody schedule based on your desire to pay no support just isn't going to fly.