Question: What place of service code would you use for interpretation of an inpatient or outpatient pulmonary function test (PFT) done in hospital-based lab? Sometimes the pulmonologist is at hospital and sometimes she interprets from office computer. New York Subscriber Answer: You should use the place of service (POS) where the testing was performed in accordance with the patient's assigned site if service: 21 (Inpatient hospital) for PFTs performed and interpreted for an inpatient, and 22 (Outpatient hospital) for PFTs performed and interpreted for an outpatient. The 2007 Review of Place of Service Coding for Physician Services, published by the Office of Inspector General, states that "Physicians are required to identify the place of service on the health insurance claim forms that they submit to Medicare contractors. The correct place-of-service code ensures that Medicare does not incorrectly reimburse the physician for the overhead portion of the payment if the service was performed in a facility setting."