Materials found in nature exhibit behaviors with certain properties such as mass density, permeability, and permittivity. Unfortunately, there are limitations and restrictions to the behaviors of these materials that can be overcome with the use of metamaterials. To improve the capabilities of metamaterials, three-dimensional metamaterials were created into planar metamaterials called metasurfaces. The transition making them from three-dimensional to two-dimensional resulted in the properties being controlled changing. Whereas three-dimensional electromagnetic metamaterials typically utilize the properties of negative permittivity and negativity permeability, metasurfaces use surface impedance to change properties such as polarization, beam shaping, and angle of reflection. This thesis examines additive manufacturable metasurfaces through a sinusoidally modulated antenna and polarization splitting metasurface. In order to design the metasurfaces, the ideas of periodicity are explored along with impedance boundary conditions. Using an isotropic impedance boundary condition and periodic unit cells of cylinders of varying heights, the design of a sinusoidally modulated is discussed. The antenna is designed with two different materials to examine the versatility. The metallic antenna is designed for broadside and non-broadside propagation and also simulated with the non-ideal conductive material. The simulation results showed the antenna with a propagation corresponding to its designed parameters. In addition, the non-ideal materials performed almost identically to the PEC antenna. The metasurface was also designed using periodic boundaries, but utilized a tensor as impedance making the metasurface anisotropic. The metasurface performs as a polarization splitter such that depending on the excitation mode, the angle the beam is steered is different. This is designed using five different unit cells of varying phases, each with three-layers to introduce an extra degree of freedom for impedance. Results for each unit cell are provided including the magnitude and phase of each unit cell.Using a commercial 3D~printer, the two metasurfaces can be produced easily. The ability of the additive manufacturing electromagnetic devices allows easy access to components with different functions at low cost. Although demonstrated with a center frequency of 15~GHz, the antenna can easily be adapted for a design with any center frequency and pointing angle at the limitations of the preciseness of the additive manufacturing printer. The ability of the adaptable designs allows antennas to be designed for the specific need of the person, such as testing in an anechoic chamber, at a low cost and quick production time. Another advantage of this antenna is the fact that it is excitable with a simple coaxial cable structure in the center of the antenna which cannot be done currently with transmit arrays and other current technologies.