Revenue Cycle Insider

Question: A 42-year-old established patient returns to the primary care office for an in-person follow-up after six months of intermittent, nonbloody diarrhea, along with bloating and urgency. Earlier stool studies, basic laboratory testing, and medication review did not identify an infectious, inflammatory, or medication-related cause. Since the last visit, the patient has kept a food-and-symptom diary and reports a reproducible pattern: symptoms occur after consuming products containing conventional cow’s milk with A1 beta-casein but do not occur with A2-only milk or when cow’s milk is avoided. The patient has had no diarrhea for three weeks while avoiding A1-containing dairy products. The physician reviews the diary and prior negative workup, documents evaluating the patient for ongoing diarrhea and a suspected A1 beta-casein food intolerance as the likely cause of the problem, counsels the patient on avoidance and nutritional substitution, and advises follow-up if symptoms recur. How do I code this encounter?

Connecticut Subscriber

Answer: For the encounter, look to an evaluation and management (E/M) code that covers an established patient and low medical decision making. For this encounter, you can report 99213 (Office or other outpatient visit for the evaluation and management of an established patient, which requires a medically appropriate history and/or examination and low level of medical decision making. When using total time on the date of the encounter for code selection, 20 minutes must be met or exceeded.).

The diagnosis coding can be a bit tricky. In this situation, the physician documents a suspected intolerance rather than a confirmed diagnosis. Outpatient guidelines instruct coders to code to the highest degree of certainty supported by the documentation; symptom codes are acceptable when a diagnosis has not been established.

Since the patient presented for help addressing their ongoing diarrhea, reporting R19.7 (Diarrhea, unspecified) could be justified when supported by the documentation. Even though the patient reports that the diarrhea has stopped with dietary modification, the encounter is still focused on the physician’s evaluation and management of the diarrhea. The outpatient guidelines allow symptom codes when a definitive diagnosis has not been established and instruct coders to code to the highest degree of certainty known for the encounter.

You should not report the intolerance as a confirmed condition unless the provider establishes that diagnosis. In this scenario, the documentation does not support assignment of a more specific ICD-10-CM code for the suspected A1 beta-casein intolerance itself — and, at this time, no such code exists.

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