There are not enough code numbers available in ICD-9 for every dx out there. That is why the rest of the world, including us in the near future, uses ICD-10 or ICD-11.
There are a lot of dx options not represented in ICD-9, controlled or uncontrolled HTN is a great example.
Diagnosis are not driven by coding books, coding books are driven by diagnosis, the books are just not as complete as we would like for them to be or even really need them to be.
It is very frustrating when they tell us we have to code to the highest level of specificity but the book doesn't allow us to really do that in many cases.
Laura, CPC, CEMC