Dawn Moreno discussed this topic in the April 2015 Q&A Webinar. In summary, you do not usually add an E/M to an outpatient procedure because the E/M was probably done a different day to determine a procedure needed to be done. Procedures have built into them a quick overview the day of the procedure. If there actually was a significant, separately identifiable E/M service provided then it can be added (show the documentation) and append modifier -25.
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