Massachusetts has very limited options in order to have the child support obligations go away. There is a case Rosen v. Rosen in 2016 that allows very limited amount of exceptions, but it is a fairly technical requirement for retroactive child support for the court to actually allow that.  You would need to file a Complaint for Modification and you need to be able to argue a limited exception that a Judge in compelling circumstances may apply a credit and calculating the child support to reflect payments that were made in a manner that was different that would have been in the original child support order; or if there had been a prior promise or an agreement that was intended by the parties to have a legal action. 

Basically, if the person that receives child support said
that he/she would accept less child support in exchange for some other promise
then in some cases that can retroactively modify the child support.  There can be a possibility if the child
changes homes between the parents, but again, very limited.  Further there can be negotiations either with
the Department of Revenue and/or the parent receiving the child support that
the judge will allow even if the judge wouldn’t order that. Again, it is a narrow
exception but there are some that are allowed.