Ohio Subscriber
Answer: CPT considers peak flow rate an inherent part of the E/M service and does not provide a distinct code for the diagnostic test. A HCPCS Level II code does exist for this service (S8110, Peak expiratory flow rate [physician services]). But insurers may follow Medicare's lead and consider S8110 incidental to pulmonary function testing and E/M services, as Empire State Medicare Services does.
Better practice: When a pulmonologist uses the handheld peak flow meter, you should instead include the diagnostic test in the E/M service. Count the measurement as part of "the amount and/or complexity of data to be reviewed" medical decision-making element.
Coders sometimes mistakenly report peak flow rate with 94150 (Vital capacity, total [separate procedure]), but 94150 describes computerized spirometry, not peak flow measurement.
You should also not report peak flow rate with 94250 (Expired gas collection, quantitative, single procedure [separate procedure]). Pulmonary function technologists frequently perform this test as part of a pulmonary stress test (94620, Pulmonary stress testing; simple [e.g., prolonged exercise test for bronchospasm with pre- and post-spirometry] and 94621, ... complex [including measurements of CO2 production, O2 uptake, and electrocardiographic recordings]), and thus it is incidental to 94620-94621.