The invention is directed to modified T cells, methods of making and using isolated, modified T cells, and methods of using these isolated, modified T cells to address diseases and disorders. In one embodiment, this invention broadly relates to TCR-deficient T cells, isolated populations thereof, and compositions comprising the same. In another embodiment of the invention, these TCR-deficient T cells are designed to express a functional non-TCR receptor. The invention also pertains to methods of making said TCR-deficient T cells, and methods of reducing or ameliorating, or preventing or treating, diseases and disorders using said TCR-deficient T cells, populations thereof, or compositions comprising the same.