Determining the Appropriate Primary ICD-9-CM Diagnosis Code

Determining the Appropriate Primary ICD-9-CM Diagnosis Code for Diagnostic Tests Ordered Due to Signs and/or Symptoms

If the physician has confirmed a diagnosis based on the results of the diagnostic test, the physician interpreting the test should code that diagnosis. The signs and/or symptoms that prompted ordering the test may be reported as additional diagnoses if they are not fully explained or related to the confirmed diagnosis.

Example 1: A surgical specimen is sent to a pathologist with a diagnosis of “mole.” The pathologist personally reviews the slides made from the specimen and makes a diagnosis of “malignant melanoma.” The pathologist should report a diagnosis of “malignant melanoma” as the primary diagnosis.

Example 2: A patient is referred to a radiologist for an abdominal Computed Tomography (CT) scan with a diagnosis of abdominal pain. The CT scan reveals the presence of an abscess. The radiologist should report a diagnosis of “intra-abdominal abscess.”

Example 3: A patient is referred to a radiologist for a chest X-ray with a diagnosis of “cough.” The chest X-ray reveals a 3 cm peripheral pulmonary nodule. The radiologist should report a diagnosis of “pulmonary nodule” and may sequence “cough” as an additional diagnosis.


If the diagnostic test did not provide a definitive diagnosis or was normal, the testing facility or the interpreting physician should code the sign(s) or symptom(s) that prompted the treating physician to order the study.

Example 1: A patient is referred to a radiologist for a spine X-ray due to complaints of “back pain.” The radiologist performs the X-ray, and the results are normal. The radiologist should report a diagnosis of “back pain” since this was the reason for performing the spine X-ray.

Example 2: A patient is seen in the ER for chest pain. An Electrocardiogram (EKG) is normal, and the final diagnosis is chest pain due to suspected gastroesophageal reflux disease (GERD). The patient was told to follow up with his primary care physician for further evaluation of the suspected GERD. The primary diagnosis code for the EKG should be chest pain. Although the EKG was normal, a definitive cause for the chest pain was not determined.

If the results of the diagnostic test are normal or non-diagnostic and the referring physician records a diagnosis preceded by words that indicate uncertainty (e.g., probable, suspected, questionable, rule out or working), then the interpreting physician should not code the referring diagnosis.

Rather, the interpreting physician should report the sign(s) or symptom(s) that prompted the study. Diagnoses labeled as uncertain are considered by the ICD-9-CM Coding Guidelines as unconfirmed and should not be reported. This is consistent with the requirement to code the diagnosis to the highest degree of certainty.

Example: A patient is referred to a radiologist for a chest X-ray with a diagnosis of “rule out pneumonia.” The radiologist performs a chest X-ray, and the results are normal. The radiologist should report the sign(s) or symptom(s) that prompted the test (e.g., cough).