There is an edit between these two codes. The XS modifier can be used to override the edit for procedures where separate lesions are involved. I think because CPT 43249 is not a procedure performed on a lesion, it may not fall under this category.
NCCI edits:
"If the corresponding procedures are performed at the same patient encounter and in contiguous structures, NCCI PTP-associated modifiers should generally not be used."
Here is the exception:
"Biopsy performed at the time of another more extensive procedure (e.g., excision, destruction, removal) is separately reportable under specific circumstances. If the biopsy is performed on a separate lesion, it is separately reportable. This situation may be reported with anatomic modifiers or modifier 59 or XS."
The treatment of contiguous structures in the same organ or anatomic region does not generally constitute treatment of different anatomic sites.
Basically, even if the biopsy was technically performed in a separate area during the EGD, it could still be considered inclusive, because these are all contiguous structures. This is just my guess and past experience however I'm not sure if there is a loophole to this.
