Neurology & Pain Management Coding Alert

Question: Is there a way to indicate on the claim form whether carpal tunnel syndrome (CTS) is bilateral or unilateral (Medicare specifies different allowances for motor nerve conduction studies for each)? Should modifier -50 be used to indicate a bilateral procedure?

Washington Subscriber

Answer: CTS is a diagnosis, and as such there is no modifier, either CPT or HCPCS, that can be attached to indicate whether the condition is uni- or bilateral. Rather, to indicate unilateral CTS, attach HCPCS modifiers -LT (left side) or -RT (right side) to the appropriate CPT code to describe the procedure performed (whether diagnostic or surgical), along with a diagnosis of CTS. For example, if the patient has CTS in the left wrist, and electromyography is performed on that wrist, submit 95860 (needle electromyography, one extremity with or without related paraspinal areas) with modifier -LT attached and a diagnosis of 354.0 (carpal tunnel syndrome). Bilateral EMGs are reported 95861 ( two extremities),  not 95860-LT, 95860-RT. Do not attach modifier -50 (bilateral procedure) to 95861, because this code already specifies two extremities. If a neurologist provides only the interpretation (e.g., the EMG is performed in the hospital, using its equipment) modifier -26 (professional component) should be appended to the EMG code.
  
Modifier -50 (bilateral procedure) generally applies to surgical procedures and some diagnostic procedures, e.g., H-reflex studies, 95934 and 95936, when performed bilaterally. Individual nerve conduction studies and electromyographies, however, stand alone and may be billed without the modifier. Nor should modifier -50 be attached to an E/M service. Rather, the complexity of the diagnosis is reflected in the level of service. Modifier -50 should be attached only if the CPT code descriptor does not already include the term "bilateral."