Ion Vapor Deposited (IVD) and electrodeposited Al coatings are potential replacements for electrodeposited low hydrogen embrittlement (LHE) Cd coatings on high strength steel substrates due to its sacrificial protection nature. As compared to LHE Cd coating which needs a post baking process to remove hydrogen both IVD and electroplated Al coatings doesn’t introduce any hydrogen during plating process. But in corroding environment there is inherent evolution of hydrogen which might diffuse through the coating into substrate and cause hydrogen embrittlement. Electrochemical permeation cell technique is used to study the effective diffusivity of hydrogen for IVD and electrodeposited Al coating using LHE Cd coating as a base line. The effective diffusivities obtained from galvanostatic charging was simulated using the classical diffusion equation to obtain hydrogen permeation flux and subsurface concentration. The effective diffusivities of hydrogen in Al coated steel will be further utilized to understand hydrogen embrittlement susceptibility by mechanical property measurements on Al coated aerospace high strength steels and components.