# Preoperative vs. postoperative diagnosis



## Brookecs

If both a preoperative and postoperative diagnosis is known when coding the medical record at a ASC, would both be coded?  According to ICD-9 guidelines for outpatient services, "if the postoperative diagnosis is known to be different from the preoperative diagnosis at the time the diagnosis is confirmed, select the postoperative diagnosis for coding, since it is the most definitive."  I have been told that the preoperative diagnosis should be coded first (if the postoperative diagnosis is different) followed by the postoperative diagnosis.  Can someone please clear this up for me?  I'm taking my CCS exam tomorrow and want to make sure I am positive on this issue.

Thanks!
Brooke Stevenson
CPC


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## Jamie Dezenzo

see in the front of your ICD-9 book "coding guidelines" Section IV. Diagnostic Coding and Reporting Guidelines for Outpatient Services

O. Ambulatory Surgery
For ambulatory surgery, code the dx for which the surgery was performed. If the post-op dx is known to be different from the pre-op dx at the time the diagnosis is confirmed, select the post-op dx for coding, since it is the most definitive.

Hope this helps!


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## magnolia1

I code Amb Surg. cases and always go by post-Op dx (except in the case of where a Pathology report comes back without a definitive diagnosis, then I will us the noted Pre-op sign/ symptom or diagnosis.


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## mbort

I agree with all, post op diagnosis (the most definitive).


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