Metamaterials are artificially structured materials possessing exotic electromagnetic or acoustic properties that are not readily available in nature, for instance synthesizing negative, zero, or very large index of refraction. Their exotic features are typically as- sociated with narrow bandwidths and losses. In this talk, we introduce the concept and theoretical modeling of parity-time (PT) symmetric metasurface pairs and metamate- rials, which offer a unique solution to these issues, realizing loss-compensated, broad- band wave manipulation, including negative refraction, cloaking and planar focusing. We discuss the largely uncharted scattering properties of PT-symmetric metamaterials and metasurfaces, with an emphasis on the exciting mathematical and physical aspects involved in these problems.