Internal Medicine Coding Alert

Find out what blood-draw and analysis codes you can report separately.

Pulmonary stress tests (PST, a.k.a. exercise testing) come in handy when your internist wants to evaluate a patient with symptoms of shortness of breath, stridor and/or wheezing that occurs only when exercising. You can pick out one from the two code options that describe a PST, and discern the difference by the amount of equipment a test requires. CPT 94621 (Pulmonary stress testing; complex [including measurements of CO2 production, O2 uptake, and electrocardiographic recordings]) calls for more equipment, but what other clues spell the difference from 94620 (Pulmonary stress testing; simple [e.g., 6-minute walk test, prolonged exercise test for bronchospasm with pre- and postspirometry and oximetry])?

The good news is you can say yes to stress-free PST billing by adopting these SOPs (standard operating procedures).

1. Know When to Use Simple Vs. Complex PST

You have a choice between two codes: simple (94620) and complex (94621) PST. The two procedures surely differ from one another, but both procedures measure exercise tolerance and the cardiorespiratory responses to the exercise.

Difference: Code 94621 is much more complex and requires more equipment because it analyzes exhaled gas (CO2 production, O2 uptake) and measures electrocardiographic responses to stress. In addition, this procedure also records data on peak cardiovascular and ventilator responses. After the internist has analyzed, evaluated, and interpreted the results of these metabolic ests, he will have to generate a written report.

You have a number of codes to use for specific exhaled gas analyses when coding 94621. For instance, if an internist ordered arterial blood gas analysis to be performed during the complex pulmonary stress exercise, you would bill the blood draw and analysis separately using 36600 (Arterial puncture, withdrawal of blood for diagnosis), 82803 (Gases, blood, any combination of pH, pCO2, pO2, CO2, HCO3 [including calculated O2 saturation]) or 82805 (Gases, blood, any combination of pH, pCO2, pO2, CO2, HCO3 [including calculated O2 saturation] with O2 saturation, by direct measurement, except pulse oximetry).

Example: A 70-year-old male patient has unexplained dyspnea (786.09) which interferes with his ability to work and exercise. The internist orders a complex PST after other studies fail to identify the cause of the dyspnea. CPT 94621 measures the cardiac and pulmonary responses to exercise and the status of the patient's physical fitness. The test measures the patient's CO2 production, O2 uptake, ventilation, and other pulmonary parameters in addition to cardiac responses using a graded exercise protocol. The internist interprets the data measuring peak cardiovascular and ventilator responses, and determines if the patient has cardiorespiratory disease or is merely deconditioned.

2. Identify the Purpose of the Test

Your internist usually orders a simple pulmonary exercise test (94620) to determine the patient's exercise capacity. Medical necessity and successful reimbursement for 94620 coincides with the following conditions:

• those experiencing unexplained shortness of breath, chronic bronchitis and emphysema, pulmonary hypertension, or pulmonary fibrosis;
• those undergoing pre-op evaluation for a lung transplantor major lung surgery;
• those subjected to disability evaluation for the severity of an occupational lung disease (e.g., asbestosis);
• those undergoing evaluation to meet Medicare's requirement for supplemental oxygen use during exercise.

Meanwhile, a complex pulmonary stress test (94621) is necessary when pursuing an underlying cause (cardiac or pulmonary) for a patient's dyspnea. When coding either test, however, you should not overlook the importance of proper documentation.

Risk: Without the appropriate documentation, some payers might mistake your 94620 claim for multiple determination of oximetry (94761, Noninvasive ear or pulse oximetry for oxygen saturation; multiple determinations [e.g., during exercise]).

Documentation for simple pulmonary exercise testing should include the patient's heart rate, distance walked, dyspnea gradation, and pulse oximetry values along with any symptoms the patient may experience during testing.

3. Avoid an Unbundling Compromise

The Correct Coding Initiative (CCI) bundles 94010 (Spirometry, including graphic record, total and timed vital capacity, expiratory flow rate measurement[s], with or without maximal voluntary ventilation), 94060 (Bronchodilation esponsiveness, spirometry as in 94010, pre- and post-bronchodilator administration), and 94070 (Bronchospasm provocation evaluation, multiple spirometric determinations as in 94010, with administered agents [e.g., antigen(s), cold air, methacholine]) with both simple and complex PST.

You can get around the bundles by appending modifier 59 (Distinct procedural service) to these codes when appropriate circumstances for unbundling exist (e.g., separate testing session).

"This is not much of a problem with 94621, but 94620 is commonly measured along with 94010 and 94060, so modifier 59 has to be placed on the spirometry codes," warns Alan L. Plummer, MD, professor of medicine in the division of pulmonary, allergy, and critical care at the Emory University School of Medicine in Atlanta.

For instance, if your internist wants to get paid for both a simple PST and spirometry, you will overcome the threat of denials by billing 94620, 94010-59.

4. Get Over the Controversy of 6MWT

When you're billing a 6-minute walk test (6MWT), you may be facing a long-standing controversy on how to bill it. A 6MWT measures how well a patient performs during exercise and the distance he is able to achieve, says Jill M. Young, CPC, CEDC, CIMC, of Young Medical Consulting in East Lansing, Mich.

An internist may require that a patient undergo a 6MWT to decide whether to prescribe oxygen during ambulation and exercise, adds Donna Ferreira, CPC, of Pulmonary Care PC in Fall River, Mass. Chronic obstructive bronchitis (491.20), emphysema (492.8), and pulmonary hypertension (416.0) are some of the conditions that may warrant a 6MWT.

The common practice is to report 6MWT as 94620. Make sure to measure the patient's heart rate, distance walked, dyspnea gradation, and pulse oximetry. Note the patient's symptoms during the test. Also, the physician must provide an interpretation of results.