In order to code carpal tunnel syndrome G56.01 or G56.02, does there need to be documentation that nerve conduction (EMG testing) has been performed to confirm the diagnosis?
Really it depends on the normal medical diagnostic practices as well as the requirements of the payer. For CTS, there are physical exam findings (non EMG testing) which support the diagnosis and typically providers say "these symptoms with this patient history = carpal tunnel syndrome" so it would be appropriate as long as the physical exam findings support it.
However, if there is a need for more extensive procedures such as surgery, it is necessary to find out what the patient's insurance payer requires, which may be further testing to confirm the physical exam findings.