Question: Answer: If a nurse simply performs the finger-stick test and does not perform a medically necessary E/M, you should report 85610 (Prothrombin time) with modifier QW (CLIA waived test). If instead, the nurse or another provider clearly documents the medical necessity for an E/M visit, you may use 99211 (Office or other outpatient visit for the evaluation and management of an established patient, that may not require the presence of a physician) in addition to 85610-QW. Cardiology practices frequently report 99211 in addition to 85610-QW because patients who come in for Coumadin monitoring can have co-existing conditions or complications that arise from time to time. But watch out: