Michigan Subscriber Answer: Spirometry (pre- or post-) is not part of the testing when your pulmonologist orders a six-minute walk test (6MWT). The 6MWT measures the distance walked over six minutes -- the pulmonary function technologist encourages the patient to walk as fast as possible throughout the test, and the technologist measures the patient's oxygen saturation, heart rate and dyspnea.
This is a simple pulmonary stress test. Because the pulmonologist requests the test, you should report 94620 (Pulmonary stress testing; simple [e.g., 6-minute walk test, prolonged exercise test for bronchospasm with pre- and post-spirometry and oximetry]) for the 6MWT.
Note: If the pulmonologist also orders spirometry or spirometry before and after bronchodilator, report it separately from the pulmonary stress test. Add modifier 59 (Distinct procedural service) to 94010 (Spirometry, including graphic record, total and timed vital capacity, expiratory flow rate measurement[s], with or without maximal voluntary ventilation) or 94060 (Bronchodilation responsiveness, spirometry as in 94010, pre- and post-bronchodilator administration) to indicate that the test is a separate test from 94620.
If the documentation is appropriate, it will support the use of modifier 59 (Distinct procedural service), which unbundles the National Correct Coding Initiative edit that includes 94010 in 94620.
Bonus: In CPT 2007, the 6MWT is listed in the descriptor for 94620, which should eliminate much of the historical confusion in coding 94620.