Coding Corner: 4 Steps to NCS Reimbursement

Hint: Identify the nerves tested, experts say

If you're confused when the physician stimulates or records multiple nerve fibers during nerve conduction studies (NCS), take heart: NCS claims can be a snap with the right tools and a little coding direction. Follow these four expert-approved steps for foolproof NCS claims.

Step 1: Determine the Nerve Fiber Type
CPT includes three codes to describe NCS:
  95900 - Nerve conduction, amplitude and latency/velocity study, each nerve; motor, without F-wave study
  95903 - ... motor, with F-  wave study
  95904 - ... sensory.
Before you select an NCS code, you must determine which nerve fiber types the physician tested.
All nerves contain motor fibers, sensory fibers or a mixture of the two, says Neil Busis, MD, director of the neurodiagnostic laboratory at the University of Pittsburgh Medical Center at Shadyside.
Codes 95900 and 95903 describe motor fiber testing (the former without F-wave study, the latter with F-wave study), while code 95904 describes sensory or mixed fiber testing. During NCS, the physician places a stimulating electrode at one location along the nerve and a recording electrode at another location along the same nerve. The stimulating electrode delivers a low-level electrical charge, while the recording electrode measures the resulting nerve function.
Example: The physician places stimulating electrodes on the radial motor nerve with recording electrodes at the extensor indicis proprius. He conducts the test without F-waves. Because this nerve contains motor fibers only, you should report one unit of 95900, Busis says. If the physician had included an F-wave study, you would report 95903 instead.
If the physician tested a sensory nerve, such as the median sensory nerve, 95904 would be appropriate. If he tested a single nerve containing both sensory and motor fibers (such as the median mixed nerve in the palm, which connects to the lumbrical muscles), you would report 95904.
Step 2: Count Billable Units
Important: Report multiple units of NCS when appropriate, because failing to do so will seriously compromise your reimbursement.

The number of billable units does not necessarily correspond to the number of extremities the physician tests, says Tiffany Schmidt, JD, policy director for the American Association of Electrodiagnostic Medicine (AAEM). Rather, the number of billable units depends on the number of nerves that the physician tests. "We are encouraging people to use the list of nerves published in the April 2003 CPT Assistant," Schmidt says.
Note: View the nerve list on the AAEM site at http://www.aaem.net/aaem/practiceissues/RecPolicy/ListofNerves.cfm.
Coding example 1: The physician studies the median motor nerve to the abductor pollicis brevis and then tests the median motor nerve to the first lumbrical. You should report [...]

- Published on 2004-08-23