The Westinghouse-led accident tolerant fuel (ATF) program is evaluating Accident Tolerant Fuel (ATF) coatings of MAX phase (Ti2AlC) and multi-layer TixAl1-xN/TiN to enhance the oxidation resistance of zirconiumalloy fuel cladding in both normal operation and beyond design-based conditions. A variety of coating technologies have been applied to deposit these coating materials onto Zircaloy-4 or ZIRLO®1 sheets and tubes, including cold spray and cathodic arc-physical vapor deposition (CA-PVD). Neutronic analysis using the elemental compositions of the coating materials showed that the coating thicknesses should be less than 30μm for most coating materials to avoid non-negligible economic penalty. The coated samples were autoclave tested in water at 360°C and 150 bar or in steam at 427°C and 103 bar for corrosion resistance evaluation. The initial Ti2AlC coating made by using large particle size MAX phase powder and cold spray deposition did not provide the desired corrosion resistance due to un-optimized microstructure and porosity. Subsequent optimization including reduction in particle size and tuning of cold spray deposition parameters resulted denser coatings less than 30 microns in thickness. Optimization of process conditions resulted in reduced oxidation kinetics and showed that the coating acts as an effective barrier to prevent the zirconium substrate from oxidizing in accident condition temperatures. High purity Ti2AlC powder is needed to further improve oxidation resistance of the Ti2AlC coating. The oxidation resistance of pure monolithic MAX phase compound was also found to be remarkable, and the weight gain was only 1.85 mg/cm2 for 96 hours exposure in 1200°C steam, which is consistent with the literature. The corrosion resistance of the TiAlN/TiN multilayer coating was excellent. The weight gain was negligible and no oxidation was observed on the surface of zirconium-alloy at the coating-substrate interface.