Neurosurgery Coding Alert

Use this 3-step guide to chart your path to accurate coding.

Choosing the appropriate code to describe your nerve conduction test can prove to be a challenging proposition -- until you learn three key areas to study. Follow these steps to make the right choice every time.

Differentiate Between Code Choices

Physicians use nerve conduction studies (NCS) to evaluate the function and electrical conduction of motor and sensory nerves in the body. When you face NCS coding, CPT offers three options:

• 95900 -- Nerve conduction, amplitude and latency/ velocity study, each nerve; motor, without F-wave study
• 95903 -- ... motor, with F-wave study
• 95904 -- ... sensory.

First step: Carefully review the physician's documentation for the individual nerves stimulated, says Marianne Wink, RHIT, CPC, ACS-EM, an independent consultant in Rochester, N.Y. Remember you can report only one unit of service of the corresponding NCS code when the neurologist performs a diagnostic study on the same nerve at multiple sites.

Report codes 95900, 95903, and 95904 by "each nerve," according to their CPT descriptors. Make sure you follow this guide and aren't reporting multiple units of service for NCS testing at multiple sites on the same nerve as "separate nerves."

"Use 95900, 95903, and/or 95904 only once when the provider stimulates or records multiple sites on the same nerve," Wink says. Code 95903 includes both the F-wave study and the underlying motor nerve conduction study. According to National Correct Coding Initiative (CCI) edits, you can't bill both 95900 and 95903 for motor NCS testing on the same nerve. CCI considers the Column 2 code, 95900 as a component of the more comprehensive Column 1 code 95903.

Know When to Add Modifiers

Modifiers can come in handy when coding nerve conduction studies, especially when the physician tests different nerves or nerve branches or performs different diagnostic NCS.

Example 1: The physician performs a motor NCS without F-wave on the right motor ulnar nerve to the abductor digit minimi (ADM) muscles. During the same procedure, he also performs a motor nerve conduction study with F-wave on the right radial motor nerve to the extensor digitorum communis (EDC) muscle.

Because the physician conducted the diagnostic studies on different nerves, report 95900 for the first motor NCS and 95903 for the second. Assign modifier 59 (Distinct procedural service) to the 95900 code to indicate that the physician performed a separate motor NCS on a different nerve.

Example 2: A physician performs motor nerve testing (95900) on the median motor nerve to the abductor pollicis brevis (APB) muscles, the ulnar motor nerve to the ADM, and radial motor nerve to the EDC muscles on the patient's left side. The doctor then performs a motor F-wave (95903) on the median motor nerve to APB and ulnar motor nerve to ADM, again on the left side.

Submit 95903 for two units and 95900-59 for one unit. Here's why: according to CCI, the 95900 procedure is bundled into 95903 when the doctor performs an F-wave study -- as well as a regular motor nerve study (95900) -- on the same nerve (as in the example above).

Because 95903 is the primary code describing the more substantial procedure, bill it on the first line. Report 95900 with modifier 59 appended on the second line for the additional, separate radial motor nerve to EDC NCS.

Warning: Even with modifier 59, you might still receive denials. Some payers, for example, might miss the modifier when processing the claim and reject the 95900 test because they say it bundles into 95903. Appeal the incorrect denial using your doctor's documentation to clearly show he tested two distinct and separate motor nerves (one diagnostic study with F-wave and one without the F-wave study).

Establish Medical Necessity

"The patient's signs and/or symptoms or a confirmed diagnosis support medical necessity when ordering a diagnostic procedure," Wink says. "The physician must document the information in the order and note for the procedure." Information supporting medical necessity should also be in the professional interpretation report for the diagnostic study.

Watch: NCS studies look for underlying conditions or injuries that could cause compromised nerve function. Because of this, numbness, tingling, weakness, and loss of sensation are all symptoms that can help support medical necessity for the diagnostic study, particularly when the final interpretation indicates normal NCS.

Also check your physician's documentation for confirmed diagnoses that could contribute to improper nerve function (such as diabetes, rheumatoid arthritis, alcoholism, etc.). Remember, however, that coding these types of conditions alone won't justify NCS. Check for documentation of symptoms the physician evaluates (such as numbness, 782.0, Disturbance of skin sensation) that can help support testing. "The other condition is a reason why the physician might think the patient need NCS," says Catherine French, manager of medical economics with AANEM in Rochester, Minn. "For example, the patient might have numbness and be a diabetic. Therefore, it's reasonable to look for neuropathy."

"Always code a confirmed condition if it's documented," Wink adds. "Otherwise, use symptoms the patient presented with. Code systemic conditions like diabetes as secondary to further support medical necessity of the diagnostic procedure."

Tip: Check your local or national reimbursement policies to verify acceptable diagnoses for nerve conduction studies. For example, payers often accept diagnoses such as 356.2 (Hereditary sensory neuropathy) or 724.4 (Thoracic or lumbosacral neuritis or radiculitis, unspecified).

Caveat: Always assign the appropriate ICD-9 codes based on your neurosurgeon's documentation. "Do not to report a diagnosis just because your payer will reimburse for it," says Wink. "Submit the most accurate diagnosis, regardless of the payer's policy."