Per the CPT book 82784 Gammaglobulin: IgA, IgD, IgG, IgM, each: Does this mean that if the provider orders each of these, we can bill 82784 X4? Or if he ordes just the IgG that this code is going to take care of all billed as X1? If the answer is X4, how do you bill on the claim form to get paid? Please advise....