Neurology & Pain Management Coding Alert

Many carriers do not understand that multiple nerves may need to be tested in a nerve conduction study (NCS) and often do not acknowledge despite the descriptions for 95900 (nerve conduction, amplitude and latency/velocity study, each nerve; motor, without F-wave study), 95903 (... motor, with F-wave study) and 95904 (... sensory or mixed) that each nerve tested is separately reimbursable, says Neil A. Busis, MD, chief of the division of neurology and director of the neurodiagnostic laboratory at the University of Pittsburgh Medical Center at Shadyside. As a result, a bill for four units of 95900 (on four separate nerves) is often reduced by carriers to payment for only one unit (as if only one nerve had been tested).

Other reasons given by carriers for reductions or denials often include ICD-9 codes that do not support medical necessity and lack of supporting documentation.

Billing for Nerves Tested

Many coders often overlook the critically important language following the definition of the three codes that specifically states they should only be reported once when
multiple sites on the same nerve are stimulated or recorded. For example, if an NCS with F-wave study (95903) was performed on three sites along one nerve, two sites along another nerve, and four sites along a third nerve, you should bill for three units (the total number of nerves tested), not nine units (the total number of sites along the nerves tested) of 95903.

Billing 95900 with 95903

Busis says some payers uniformly reject 95900 and 95903 when they are billed together, indicating that the first code is a component of the second. But this is true only if they are reported for the same nerve, not if the NCS without F-wave (95900) was performed on one nerve and the NCS with F-wave (95903) on another.

The key, says Tiffany Eggers, JD, MPA, policy director and legislative counsel for the American Association of Electrodiagnostic Medicine, is to ensure that documentation sent with the claim clearly shows that separate nerves were tested.

Otherwise, carriers are going to look at the two codes, decide you are trying to unbundle and deny the claim, she says.

Use of Modifiers with NCS

HCFA has suggested that modifier -59 (distinct procedural service) be used with each NCS code following the primary to indicate that they represent separate services performed on different nerves. Busis says this may attain reimbursement, but it is incorrect coding. These codes are designed to be billed per nerve with no modifier needed, yet payers generally do not recognize this. Until HCFA releases more clarifying information, using modifier -59 may be the only way to obtain optimum reimbursement for multiple testing at different sites.

Some neurology coders face denials due to the use of inappropriate modifiers such as -51 (multiple procedures). Busis says that under no circumstances should an NCS code be appended with modifier -51 because all these codes are exempt. Another incorrect modifier that often prompts rejections is modifier -76 (repeat procedure by same physician). It should not be used for an NCS, because carriers are accustomed to seeing it appended to failed surgical procedures that need to be attempted later. The use of it generally results in payer confusion and denials.

Coding for Studies of Multiple Nerve Branches

Because of the rule that multiple sites along a single nerve cannot be billed, neurology coders dont realize that it is possible to be reimbursed for NCS of two or more branches of a given motor of sensory nerve. This uncertainty leads to many claims not being filed (or filed incorrectly) and lost potential reimbursement.

Busis says that while carriers detail specific criteria that must be met and documented in the patient record to gain reimbursement for NCS to the primary and multiple nerve branches, there are no requirements to submit documentation with the claim. However, without it traditionally in the form of a letter including the information that must be posted in the patients medical record these claims are usually paid.

Carriers will see only a list of codes, assume that the claim is for additional sites on a single nerve, and issue a denial. They will not understand that primary and multiple nerve branches were addressed unless you communicate that during the NCS, the stimulating and recording electrodes were moved to different locations (e.g., from the primary nerve to each of the nerve branches tested).

It may also be necessary to remind the carrier of its own rules for payment of NCS to primary and multiple nerve branches, because the representative reviewing your claim may not be aware of all guidelines for these studies. Communicate these basics to a carrier:

1. If the primary nerve and two branches were tested but the electrodes were not moved, you may bill, for example, 95900 only once.

2. If the primary nerve and the two branches were tested, and the recording electrodes were moved from the primary to each of the nerve branches, 95900 could be billed three times (once for primary and two more times for the additional nerve branches stemming from the primary).

Note: This rule applies for any of the individual NCS codes.

Coding for a Mixed NCS

Eggers says many payers may also reduce or deny claims involving mixed NCS (95904) because they do not understand that although mixed nerves contain both sensory and motor fibers, it is a totally separate study from a sensory or motor NCS. If you have frequent reductions or denials of claims for these studies, explain to your carrier, either by phone or in writing, that three different types of nerves are tested:

1. Nerves that contain only motor fibers.
2. Nerves that contain only sensory fibers.
3. Nerves that contain both motor and sensory fibers.

A mixed NCS can be performed during the same patient encounter in addition to one for a motor nerve and a sensory nerve.

Confusion often arises for carriers reviewing claims for all three studies performed during a single patient encounter: Though there are only three codes for NCS, there are four different nerve conduction studies that can be performed:

1. Motor without F-wave (95900)
2. Motor with F-wave (95903)
3. Sensory (95904)
4. Mixed (95904)

Carriers often dont realize that mixed and sensory are different tests that can be performed on various nerves during one session. Although 95904 can be billed twice, carriers often do not pay for the second listing of it because they incorrectly believe this is a duplication of service.

It is crucial to ensure that the carrier understands that different nerves are tested in each study. Accompanying documentation stating this and listing the separate nerves tested may need to be sent with your claims.

Evidence of Medicares lack of understanding of these basic facts can be found in the Correct Coding Initiative (CCI) bundling of 95900 and 95903 into 95904 last June. This error was supposed to be cleared up with the implementation of CCI 6.2, but now, as we wait for CCI 7.1, the mistake has still not been corrected.

HCFA has communicated to the American Academy of Neurology (AAN) in writing that they are in the process of deleting this CCI edit. However, until an official memorandum is issued to regional and local carriers, or until the error is rectified, keep in mind that if a payer attempts to bundle 95900 or 95903 into 95904, you should use modifier -59 with either the motor (95900 or 95903) or the mixed (95904) code to ensure they remain unbundled.

Note: Because modifier -59 will result in a fee reduction, you should attach it to the code with the lower relative value unit (RVU), in this case 95900 or 95903.