BCBS Missiouri, and yes they required that occurrence span code.. they have denial codes that i didn't get it, especially it is regarding about modifier.. most of them are 018 4. 018 1. 018 07. , the last time the denial code 018 07 is in the box 44 of the ub-04 form, but the rest i don't know what box it is on the form, if just anyone can tell me i'm sure i can figure out the problem.. thanks...