Pulmonology Coding Alert

Question: Are pulmonary function tests billed with the diagnosis for which they were ordered or with the result of the test? Michigan Subscriber Answer: The diagnosis can be either the reason for the test being ordered or the outcome of the test, as long as the reason for ordering the test is not "screening." Medicare will allow you to report the outcome of the test as its primary diagnosis.

For example, if the patient came in with wheezing, and the test determined that the patient was having an acute exacerbation of asthma, you could report 493.02 (Extrinsic asthma; with acute exacerbation) as the primary diagnosis with 786.07 (Wheezing) as the secondary diagnosis. But if the patient did not present with any symptoms and had no personal history of cardiopulmonary conditions but only had a family history of emphysema, the test would be ordered as a screening service (V81.3). Medicare prohibits any other diagnosis from being reported as the primary diagnosis when the original intent was screening, even when the test uncovered a problem or condition. Be aware that only certain circumstances and diagnosis codes will support medical necessity. Documentation should be included to support the test as medically necessary. Local medical review policies spell out in depth the requirements that must be met for full reimbursement. For example, the New York State medical review policy states that lung function tests are appropriate under five circumstances:

1. To determine the presence of lung disease or abnormality of lung function

2. To determine the extent of abnormalities and the causative disease process

3. To determine the extent of disability due to abnormal lung function

4. To determine the progression of the disease

5. To determine the type of disease or lesion. Medicare excludes screening as an indication for lung function testing. Be sure to check with the carrier to determine acceptable diagnosis codes to support medical necessity. There are several examples of appropriate ICD-9-CM codes: 162.0-162.9 Malignant neoplasm of trachea, bronchus, and lung 466.0 Acute bronchitis 492.0-492.8 Emphysema 493.00-493.92 Asthma 518.81 Acute respiratory failure 780.50-780.57 Sleep disturbances 786.2 Cough 790.91 Abnormal arterial blood gases.