Primary Care Coding Alert

Question: If a provider writes out a prescription for a drug pending the results of a lab test, should we put Z79.899 on the encounter, the lab order, or both? How should we interpret the terms “current” and “long term” in this situation?

Missouri Subscriber

Answer: While you don’t say why your provider is prescribing the drug, or what kind of condition the drug is treating, using Z79.899 (Other long term (current) drug therapy) in either of these situations isn’t really appropriate.

Why? Z79.899 should only be used if the patient is taking the medication at the time of the encounter (in other words, the drug use is “current”) and has a history of taking the drug over an extended period of time (in other words, the drug use is “long term”).

While there is no accepted time period associated with the code, 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, none of the Z79 codes would apply.

In this particular situation, as the patient has yet to begin the drug therapy, your best option would be not to assign this code to the encounter or the lab order.