Part B Insider (Multispecialty) Coding Alert

Question: I coded my physician's diagnostic testing recently that included nerve conduction studies, an EMG, plus H-reflex testing. The doctor's final diagnosis was S1 radiculopathy (723.4). I billed all of the appropriate codes, plus an E/M code with modifier 25 in the following sequence:

• 99213-25
• 95903-LT x 2
• 95903-RT x 2
• 95904-LT
• 95904-RT
• 95934-LT
• 95934-RT
• 95861.

The patient's MAC denied a lot of the diagnostic studies. Why didn't we get paid for the full services provided?

Answer: When your physician performs a nerve conduction study (NCS) and you code 95903 (Nerve conduction, amplitude and latency/ velocity study, each nerve; motor, with F-wave study) or 95904 (... sensory) test, you need to code per nerve or nerve branch, not per unilateral limb.

Even though your doctor may have tested identically named nerves on both lower extremities, you don't need to indicate LT (Left side) and RT (Right side) with these codes. In fact, many payers will not process claims for NCSs with these modifiers.

You can report NCSs with the total number of tests as units of service. For example: 95903 x 4 and 95904 x 2. For the H-reflex study, you should only report 95934 (Hreflex, amplitude and latency study; record gastrocnemius/ soleus muscle) on a single line item with one unit of service for Medicare carriers. Attach modifier 50 (Bilateral procedure) to show that your physician performed this procedure on both sides of the patient's body. CPT includes a parenthetical note that says "to report a bilateral study, use modifier 50" -- which makes this neuromuscular electrodiagnostic test different from many of the other codes.

Keep in mind: You may also need to check your Medicare contractor's local coverage determination on electrodiagnostic testing. Many include units of service limitations based on the reported diagnosis similar to the "Maximum Number of Studies" table at the end of Appendix J in the CPT codebook.