The law only allows adult children to stay on their parents' health plans until 26 anyway. I don't think it's unreasonable to allow your child to stay on your insurance while they are in college. I'd want my children to have good health insurance to protect them while they are in school, and the plan my husband and I have is certainly better than what they could buy from their school. In terms of "mooching," I think being on Mom/Dad's health insurance is fairly low level. But Mom/Dad need to understand that the adult child makes their own health care decisions.
My sons will have jobs and will pay most of their own living expenses while they are in college. We are saving to help with the cost of tuition/dormitory, but if they choose a very expensive private schools, they will have to chip in with loans, etc. We might keep them on the family cell phone/car insurance plan while in undergraduate, but after that, it will be their responsibility. Plus, they'll pay for their own recreational expenses, clothing, travel, etc. If they are foolish and get credit cards and run up huge balances, they will have to work to pay them down. I'm not cosigning anything, either. I paid my own way and worked throughout college, and I think that's better than just handing kids everything - they never learn independence that way. I know people MY AGE who are still getting handouts from their parents. I honestly think that's pathetic. 👎