Neurosurgery Coding Alert

Best practice: Look for the functional component and keep a close count on the nerve(s) treated.

When coding nerve conduction studies, you may be faced with denials if you aren't reporting the code(s) for every unit of service in the nerve conduction study (NCS). Take a look at the guidance below to stay on the right path to full reimbursement.

1. Look for the Sensory or Motor Component

When coding for nerve conduction, first look for whether the physician is trying to study a motor or a sensory nerve as codes specify these two types. Motor nerves are those that carry commands of movement from the centers in the brain or spinal cord to the extremities. Sensory nerves, on the other hand, carry sensations from the periphery to the centers in the brain or the spinal cord.

You report code 95904 (Nerve conduction, amplitude and latency/velocity study, each nerve; sensory) for the conduction study in the sensory nerve. When reporting the conduction study in the motor nerve(s), you have to make a choice between 95900 (Nerve conduction, amplitude and latency/ velocity study, each nerve; motor, without F-wave study) and 95903 (Nerve conduction, amplitude and latency/ velocity study, each nerve; motor, with F-wave study). "These codes have an "xxx" global period, so reporting multiple codes is done without the 51 (Multiple procedures) modifier," says Gregory Przybylski, MD, director of neurosurgery, New Jersey Neuroscience Institute, JFK Medical Center, Edison.

2. Catch the F-Wave in Motor Nerve Monitoring

Another important step towards the right code when reporting the motor nerve conduction study is to look for the F-wave study component. The F-wave study is used to assess the conduction of impulses between the limb and the spine. This is different from the motor and sensory conduction studies that help to measure velocity between segments of a limb.

If you read in the clinical note that your physician did a 'supramaximal stimulation of a (motor) nerve and then recorded the action potentials in the muscle supplied by the nerve', you confirm that F-wave study was done. In this case, you report code 95903. "The F-wave study is actually a supramaximal stimulation of the

distal motor nerve to measure the secondary muscle response after retrograde stimulation to the motor neuron in the spinal cord followed by anterograde response from the motor neuron back to the muscle," says Przybylski.

F-wave specifics: Your physician should mention the central and the peripheral points of recording the conduction. For instance, if your surgeon is doing the F-wave study in the median nerve, there will be mention of distance (in mm) from the wrist crease to the process of the seventh cervical vertebra. Your physician includes these details in the clinical notes as this is important in the formula for the calculation of the velocity in F-wave study. When you see that no F-wave study was done, you report code 95900.

Caution: The National Correct Coding Initiative (CCI) considers the Column 2 code, 95900 as a component of the more comprehensive Column 1 code 95903. Hence, you cannot bill both 95900 and 95903 for motor NCS testing on the same nerve. "This is logical, since code 95903 contains the work of 95900 with the additional component of the F-wave study," says Przybylski.

3. Report a Single Unit of Service for One Nerve

When reporting the NCS, you should remember that you can only report a single unit of service when your physician does the study at multiple sites on the same nerve. Hence, you count the nerves and not the number of sites where the recording is done during the examination.

Remember: The CPT® descriptors for codes 95900, 95903, and 95904 mention 'each nerve'. You hence report the codes for every individual nerve that is investigated.

4. Add Appropriate Modifiers to Avoid Missing Payment

When your physician may performs the recording in two branches of the same nerve or test different nerves in the same setting. In these instances, you'll need to apply the appropriate modifiers to earn full pay.

Example: Your physician, while attempting to study the nerve conduction in the right hand, may record the velocity of conduction in the recurrent branch of the median nerve (C8, T1) that supplies the abductor pollicis brevis in the thumb and also does the NCS with F-wave recording in the deep branch of the ulnar nerve that supplies the abductor digiti minimus. In this case, you would report 95900 for the NCS in the median nerve and 95903 for the second one in the ulnar nerve. You append modifier 59 (Distinct procedural service) to the 95900 code to specify that your surgeon did a separate motor NCS on a different nerve.

When your surgeon does the NCS in different nerves and does the F-wave recording in only one, you should report code 95903 on the first line as it is describing the more substantial procedure.

You then report 95900 with modifier 59 for the additional, separate median motor nerve to the abductor pollicis brevis. Tip: To justify reporting the testing in two separate and distinct nerves (one of which involves an F-wave recording), your physician's clinical notes should clearly specify the two recordings. You can challenge any denial if you have appended the modifier 59 appropriately.

5. Select the Right Diagnosis

Your surgeon may be doing a NCS for a wide variety of clinical indications. Look for the underlying condition necessitating the study in the professional interpretation report of the NCS. Protean conditions affect the function of nerves, including diabetes, chronic alcohol use, poisoning, and injury.

You should in specific look for the symptoms that lead to the necessity of the diagnostic NCS. For example, you may look into the clinical note for descriptors like numbness, tingling, loss of sensation, altered sensation, and muscle weakness. You may report 782.0 (Disturbance of skin sensation) for numbness. In other instances, you may also report 356.2 (Hereditary sensory neuropathy) or 724.4 (Thoracic or lumbosacral neuritis or radiculitis, unspecified) as appropriate. Do not forget to check with your payer for acceptance of these conditions as being necessary for NCS.