I work for an Allergist and previously we billed 94620, which has been deleted. I am trying to figure out which code I should be using now. We do all of the components of 94618 except for oxygen titration. AAAAI advised us to bill 94618 using modifier 52. I would understand if it was billed once or twice like this but this is a common ICD for us and I am nervous about billing with 52 everytime. Any recommendations?