I, too, do not agree with the codes you were told to use for steroid dependent asthma. Obviously the word dependent threw off whomever was giving you codes to use, in reference to the 304 code your were given. Just like someone with severe COPD could be O2 dependent, cases of severe asthma can be treated with oral steroids. This definitely does not fall under the 304 code range but, rather, merits a V-code as the others suggested. The E-code you were told to use would only be applicable if the steroids were the cause of any adverse effect, not just because the patient must use steroid to control the asthma. So all in all, I agree with using 493.9X and V58.65.