Who can seek custody?
Generally, both parents are entitled to seek sole or shared custody from the court. However, if the parents are unmarried, the father must first establish paternity (legal fatherhood) before seeking legal custody of his child.* Paternity can be established by a judge if one parent files a paternity petition in court, or outside of court if both parents sign and file what is called a “voluntary acknowledgement form.” You can read more about paternity and how to establish it on MassLegalHelp.org.
Grandparents may also be able to seek custody of their grandchildren in certain circumstances. See I am the child’s grandparent. Can I get custody or visitation of the child?
* M.G.L.A. 209C §§ 10(b); 11