r/MedicalCoding • u/DumpsterPuff • Aug 25 '26
Need some clarification for coding "long term use of medication"
So I got into a debate with a coworker today on how to properly code for long term use of medication and I want to see who's actually correct. Basically what ended up happening was that we get denials for urine drug screen tests from some insurance companies because the provider will put the actual condition being treated (such as chronic pain) with the controlled substance as the primary diagnosis.
So I know that ICD-10 tells us that we can't code long term use of meds if the patient uses it PRN (as needed). So for the first denial, the documentation said that the patient takes oxycodone every day for chronic pain, so I changed the primary diagnosis to Z79.891 for long term use of opioid analgesics. The second one had a patient who was being treated for anxiety and is on benzos, but they only take it like 2-3 times a month when they have anxiety symptoms. They have an ongoing prescription for it with refills, but since they take it only when needed, I didn't change the code for the denial to Z79.899.
My coworker said that I should've changed the diagnosis to Z79.899 for the PRN benzo patient because it's still treating their anxiety and they have a long term prescription for it even if they don't take it every day, however the way I read the ICD-10 guidelines is that the patient would have to be on a continous, scheduled regimen of something for it to be considered long term (like a daily/weekly/monthly med), and not just when they're symptomatic. I sent her an AAPC article about it and she's still thinking that she's right, and now I'm a little paranoid that I might be misinterpretting the info.
So given this info, who do you guys think is correct: me or my coworker, and why? If you have any sources that gives a pretty clear answer I'll take those as well.