My husband and his ex-wife share 50/50 custody of their three kids. Since the divorce, the kids have been on her health insurance because it was cheaper than his. He pays her child support due to the difference in their incomes and he also sends a separate check each month that contributes to their health insurance. We recently realized that we could put his 3 kids on my insurance because I already pay for employee and children and it wouldn't raise our rates at all. Their mom is resisting this and won't say why. We think it's because she has another child that's not his and she pays for his insurance. Hers would not go down any to take our 3 off so we'd pay less but she'd pay the same and he wouldn't give her the extra towards insurance if we are covering them. Can we move them to my insurance and stop sending the additional money anyway? His obligation is to pay for insurance for his 3...not contribute to her other child's insurance. So if we're totally providing insurance, can she say anything about him not sending the extra money?