A patient presents for an evaluation of unilateral knee pain and we do x-rays 4 views of the knee. The standing view(s) capture the contralateral side. We have always billed this scenario as 73564 with RT or LT as appropriate. There has been some discussion lately that we should bill 73560 for the contralateral views if they are interpreted on. However, I feel if the patient has no complaints on the contralateral side, the medical necessity wouldn't be there even if the x-rays reveal something such as osteoarthritis. Does anyone know of an official source that states whether the contralateral side can be billed or not in the absence of patient complaints?