Hi, I live in and got divorced in MA recently.
My situation was different because the incomes weren't close, but my understanding was that if the incomes were very close, and both parties agreed to it, the judge might allow no child support. Normally there are guidelines in the form of a worksheet (you can even find it online) but these are only guidelines, the judge doesn't have to follow them.
In my case I work for a private company, and the company's policy was ex-spouses could not be carried on the health insurance. I wish she could have been, it would have been cheaper all around but the decision ended up being out of my hands.