Unless the provider saw the patient in a previous visit for the same reason and ordered the swab as a follow up, there is no code you can charge. A 99211 as an incident to charge is for a visit that is incident to a physician having already evaluated and diagnosed the patient with a written plan of care that outlines the activity to be performed. If this patient presents symptomatic, the nurse cannot decide that a lab test wth a swab is the appropriate action, even if this is verbally discussed with the provider.