For parents in Massachusetts in even the lowest of income brackets, the Probate and Family Court has established a minimum child support payment of $25 per week. Even if the parent paying child support has no job and no prospects of finding work, the Court will require the parent to pay at least $25 per week.
This requirement comes from the Massachusetts Child Support Guidelines. The child support guidelines are published by a task force that is appointed by the Chief Justice of the Trial Court, Paula M. Carey. The guidelines are reviewed and revised roughly every 4 years. At the time I am writing this, the task force is in process of reviewing the child support guidelines for an update to be published in mid-2021.
Supporting a child is viewed as the obligation of both parents, and the courts will not usually allow a parent to waive child support. The courts take the position that child support is something that the child is entitled to, so it isn't something that the parents can negotiate. With that said though, sometimes the parents equally share parenting duties and their incomes are very similar, so there may not be a disadvantage to the child by not receiving support.
Just remember, the Probate and Family Court takes child support very seriously and doesn't look too kindly on parents that try to avoid financial obligations for their children. The best thing to do is to always try to pay some portion of child support if you can't pay the full amount. Both parents should also keep track of payments made, just in case you need documentation of it at some point.