Middlesex County Registry-prbt 208 Cambridge St Cambridge, MA 02141 Phone : (617) 768-5800 Business Category Government Offices-County Legislative Bodies State Courts County Government-Courts Courts Mass Commonwealth Of--courts, Middlesex County Juvenile Court, Middlesex County Probate And Family Court Cambridge, MA 02138 Phone : (617) 768-5800 Business Category Government Offices-City Village & Twp Government Offices-County Government Offices State & Local County Government-Courts Courts Government Offices & Public Schools Middlesex County Of--registry Of Probate Cambridge, MA 02138 Phone : (617) 768-5800 Business Category Government Offices-County Government Offices & Public Schools