Can anyone help me distinguish the difference between a peak flow, spirometry and a PFT. The doctor is ordering a spirometry and the MA's are preforming this test with the 'spirometer' machine that generates a report that says 'PFT'. Another biller is telling me that the actual spirometry is the peak flow, when the patient blows into the plastic device and they do it by hand. What is the peak flow then? Help?!?! I am so confused as to what procedure is to be billed as what and when and ......