The information on CPT 20950 that was listed below appears to be outdated and inaccurate. The most current information on this subject appears to be from August 2004, while the Ortho pink sheet that was referenced was from July 2004. The context behind the July 2004 communication stated that the AAOS and the AMA could not agree at that time on how CPT 20950 was to be billed. The quote starting with "The AMA states you can report 20950 per muscle compartment checked" was updated in the following Ortho Pink Sheet (August 2004). It states the following:
"It took some debate, but the American Medical Association (AMA) and the American Academy of Orthopaedic Surgeons (AAOS) now agree that 20950 (monitoring of interstitial fluid PRESSURE (includes insertion of device, eg, wick catheter technique, needle manometer technique)) is not billable per muscle group because any additional work to insert the catheter in different muscles of the same muscle group does not meet the requirements for individual reportage of 20950. “After considerable discussions with the coding committee of AAOS, they have provided the following guidance based on their belief that while per muscle would seem to be appropriate, the work required to install the catheter is limited and thus does not warrant reporting per muscle,” says an AMA spokesperson.
They give this example on how these codes should be used.
For instance, if your doc checks the four muscles in the leg, then you would only bill 20950 only once. However, if the doc measures the pressure in the thigh and leg you would report 20950 twice, and if the procedure was performed bilaterally, you could still bill 20950 twice by appending modifier -50 (bilateral procedure).