Primary Care Coding Alert

Question: When measuring the BMI using an electronic scale, can we use 93720 (Plethysmography, total body; with interpretation and report)?

Florida Subscriber

Answer: It would not be appropriate to use 93720 to code for a body mass index (BMI) calculation using an electronic scale. Since the measurement of the body mass index is part of the physical examination (it is computed from the weight and height of the patient), consider the measurement part of the E/M service (such as 99201- 99215, Office or Other Outpatient Services) provided to the patient. Link this to the appropriate body mass index V code, such as V85.0 (Body mass index less than 19, adult).

Plethysmography is not a procedure used to measure BMI. Although several investigators have certainly used plethysmography to determine body composition, particularly in morbidly obese cases, this test's purpose was to determine other parameters; for example body density and fat free mass, not to measure BMI. Moreover, these tests use an air displacement plethysmography rather than the total body plethysmography. Code 93720 "describes a diagnostic pulmonary evaluation that measures thoracic gas volume, compliance of the lung, airway resistance, and airway conductance," according to CPT Assistant, September 2003, page 15.