Pt-modified bond coats are known to protect the superalloy substrate during service in a severe high-temperature environment by forming a stable alumina (Al2O3) layer. However, unwanted Al loss was frequently observed because of the interdiffusion zone (IDZ) growth between the bond coat and superalloy. This complex diffusion-controlled growth of IDZ is explained based on a quantitative diffusion analysis. The diffusion coefficients estimated following the newly proposed pseudo-binary and pseudo-ternary diffusion couple methods indicate that the interdiffusion coefficient increases significantly in the presence of Pt. On the other hand, the Pd presence plays a minor role. This behaviour is further reflected in the growth rate of the interdiffusion zone between the bond coat and single crystal superalloy in the presence of Pt or Pd. However, oxidation resistance in the presence of Pt is far superior compared to Pd. The partial replacement of Pd with Pt is comparable to the presence of only Pt in the case of oxidation resistance, along with a benefit of a decreased growth rate of IDZ. The addition of Ir is beneficial for both oxidation resistance and reduced growth rate of IDZ. In this presentation, various aspects of the growth of IDZ in comparison to the oxidation resistance of the bond coat will be explained based on the estimated interdiffusion coefficients and complex diffusion-controlled microstructural evolution.