High entropy carbides are a novel class of UHTCs. Thermodynamic calculations using FactSage software and databases were performed for oxidation reactions of the constituent carbides in an equimolar, five-component carbide, (HfZrTiTaNb)C. The relative stability of the oxide phases formed from the constituent carbides and from binary carbide solutions were used to investigate selective oxidation. This analysis was extended to ternary and higher order alloys and carbides. The thermodynamic predictions were compared to the experimentally determined oxidation behavior of the five-component carbide at 1500°C-1700°C oxidized in 1%O<sub>2</sub>. Experimental results verified that Group IV oxides dominated in the observed oxide scale, resulting in a Group V enriched substrate. It was concluded that, given any high entropy material, even a slight relative favorability for a given oxide formation reaction will result in selective oxidation, reducing the configurational entropy in the remaining material.