Neurology & Pain Management Coding Alert

Identify the nerves tested to ease the path, experts say

If you find reporting nerve conduction studies (NCS) confusing, especially when the neurologist stimulates or records multiple nerve fibers, 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. 1. Determine the Nerve Fiber Type(s) Before determining which NCS codes apply, you must first know the types of nerve fibers the neurologist tested.

All nerves contain motor fibers, sensory fibers or a mixture of the two, says Neil Busis, MD, chief of the division of neurology and director of the neurodiagnostic laboratory at the University of Pittsburgh Medical Center at Shadyside, and clinical associate professor of neurology, University of Pittsburgh School of Medicine.

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 (see "What's What? A Quick Guide to NCS Terminology"  for an explanation of "motor," "sensory" and "mixed" nerve fibers).
During NCS, the neurologist 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.

Coding example: The neurologist places stimulation 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 neurologist had included an F-wave study, you would be correct to report 95903.

If, however, the neurologist tested a sensory nerve, such as the medium sensory nerve, 95904 would be appropriate. And, had 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 also report 95904. 2. Count the Billable Units You should report multiple units of NCS, when appropriate, and failing to do so will seriously compromise your reimbursement.

Don't miss: The number of billable units does not necessarily correspond to the number of nerves the neurologist tests, says Tiffany Schmidt, JD, policy director for the American Association of Electrodiagnostic Medicine (AAEM). Rather, the number of billable units depends on the movement of the stimulating and recording electrodes.

If either the recording or stimulating electrode remains stationary during the study, you may report only one unit of the appropriate NCS code. But if the neurologist moves both the recording and stimulating electrodes - even if to different locations on the same nerve - you may report multiple units of the appropriate code, says Heather Corcoran, coding manager [...]