Child support can be awarded in Massachusetts where the parties have any child that is unemancipated. In general, a child is emancipated upon the soonest to occur of age 23 or graduation from college. Provided that the parties are contributing to the costs of college, child support is discretionary for children over the age of eighteen years. To the extent that a child does not attend college but is still residing with a parent and principally dependent on that parent for support, then child support continues until age 21. The guidelines capture the first $250,000 in combined earned income of the parties. Income in excess of that can be considered for purposes of awarding additional child support or spousal support. Additional law governing child support and the definition of emancipation can be found here: https://malegislature.gov/Laws/GeneralLaws/PartII/TitleIII/Chapter208/Section28.
The Massachusetts Child Support Guidelines and Child Support Guideline Worksheet can be found here: https://www.mass.gov/info-details/child-support-guidelines.