The 99211 (nurse visit) is bundled into the flu shot, regardless of what else was done. If your physician also saw the patient, bill the appropriate E&M code based on the separately-identifiable key components (stable chronic problem is generally a 99212, but the HPI or exam also have to meet that level), then bill the CPT code for the appropriate flu vaccine, and either 90471 or G0008 (Medicare). Even if the nurse did a BP check, don't also bill the 99211. Make sure the diag for the OV is different from the flu diag-- V04.81. Some payers like the -25, but I wouldn't add it as a matter of course, check with them first.