The present invention provides isolated monoclonal antibodies, particularly human antibodies, that bind to human Cluster of Differentiation 73 (CD73) with high affinity, and inhibit the activity of CD73, and optionally mediate antibody dependent CD73 internalization. Nucleic acid molecules encoding the antibodies of the invention, expression vectors, host cells and methods for expressing the antibodies of the invention are also provided. Immunoconjugates, bispecific molecules and pharmaceutical compositions comprising the antibodies of the invention are also provided. The invention also provides methods for inhibiting the growth of a tumor cell expressing CD73 using the antibodies of the invention, including methods for treating various cancers.
