Pathology/Lab Coding Alert

Question: A patient presents to the physician office with a headache and severe vomiting. The physician orders a non-automated urinalysis without microscopy to rule out gastroenteritis. What diagnosis code(s) should I report for the lab test?

Texas Subscriber

Answer: You should not report a -rule out- diagnosis as the reason for a diagnostic test in a non-inpatient setting. That means you shouldn't code the gastroenteritis (558.9, Other and unspecified noninfectious gastroenteritis and colitis).

Instead, you should report the signs and symptoms that indicate the reason the physician ordered the test. In this case, list the following two codes:

- 787.01 (Nausea with vomiting)

- 784.0 (Headache).

Reason: You should report the diagnosis code to the highest degree of certainty. In this case, all you know about the patient's condition is the symptoms that prompted the testing. You do not know the physician's final diagnosis for the patient based on the lab test results and clinical presentation.