There is a debate in my department of when you can assign Z79.899 to cover the medical necessity for outpatient services. Some of my peers believe you can only assign Z79.899 per a short list in the appendix in the back of the Optum ICD-10-CM Expert codebook. I believe, per coding guidelines, coding clinic, and the description of the code (other long term (current) drug therapy), it can be assigned. Provided there is supported documentation of a medication not applying to a more specified Z79.xxx code. (ex: Z79.01 for someone prescribed Coumadin.)

Please provide me with anything in regard to Z79.899.