Ask Dr. Z

On question 13390, it was advised that mod 59 was not required when one physician of a group practice performed the diagnostic cath and another physician provided the intervention because they are "billed as if they are one physician." Even when one physician performs both the cath and the stenting, the cath must have modifier 59 (or appropriate X modifier), or the cath will deny because it bundles with the intervention. Can you please clarify the previous response of question 13390 that no modifier 59 is required? Thank you.