Primary Care Coding Alert

Question: In what situation should I include ICD-10-CM code Z79.899? A lot of the patients our primary care office sees are actively taking medication or have taken a medication in the past. Should this code be included on our claims?

Alabama Subscriber

Answer: Looking at the code descriptor, you can see that code Z79.899 (Other long term (current) drug therapy) should only be used if the patient has been taking the medication in question for an extended period of time (hence the term “long term”) and is still taking it at the time of the encounter in question (hence “current”).

While the code does not include a specified time period, you would generally assign it when the patient is actively taking it for a chronic illness or a condition that will last for an extended period of time. So, for example, if your provider is prescribing the medication for a short-term acute illness that will resolve in the foreseeable future, Z79 codes would not be appropriate.

Remember to base your coding on your provider’s documentation, and to query the physician when you have a specific question about a diagnosis or other element of their documentation of an encounter.

Rachel Dorrell, MA, MS, CPC-A, CPPM, Development Editor, AAPC