Who can file for custody?
Generally, both parents are entitled to file for 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.1 Paternity can be established by in court if one parent files a paternity petition in court, or outside of court if both parents sign and file what is called a “voluntary acknowledgment 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?
1 M.G.L. 209C §§ 10(b); 11