Neurosurgery Coding Alert

Just because your neurosurgeon's documentation shows he repeatedly stimulated a single nerve during neuromuscular junction (NMJ) testing doesn't mean you report multiple codes. Comb through the chart for separate and distinct nerves -- not the number of stimulations performed on each nerve -- for the most compliant coding every time.

Physicians rely on repetitive stimulation studies to identify and differentiate disorders of the NMJ, such as myasthenia gravis (358.00, Myasthenia gravis without [acute] exacerbation; or 358.01, Myasthenia gravis with acute exacerbation).

When your physician completes NMJ testing, you report 95937 (Neuromuscular junction testing [repetitive stimulation, paired stimuli], each nerve, any 1 method). That's simple enough, but the term "each nerve" in the descriptor trips up some coders when they're faced with multiple stimulations.

Tip: Submit 95937 as a single line item with the total number of separate and distinct nerves your physician tests in box 24G or the electronic equivalent.

Example: The physician repeatedly tests three separate and distinct nerves -- the ulnar motor nerve to the abductor digiti minimi muscle, the median motor nerve to the abductor pollicis brevis muscle, and the spinal accessory nerve to the upper trapezius muscle. When filing the claim, you'll report a single line item of 95937 with "3" in the units field.

Seeing documentation of what seems to be a bilateral nerve test (such as a procedure on the right and left upper extremities) doesn't mean you automatically append modifier 50 (Bilateral procedure).

Explanation: CMS assigns 95937 a "0" bilateral status indicator in the Medicare Physician Fee Schedule. That means you can't report 95937 as a bilateral procedure because "150 percent payment adjustment for bilateral procedures does not apply." Even though your physician might test the ulnar nerve on the patient's right and left extremities, CMS does not consider the testing to be bilateral.

Avoid 51: Similarly, don't report 95937 as separate line items with modifier 51 (Multiple procedures) because the Medicare Physician Fee Schedule assigns the code a "0" multiple procedure discount status indicator. The "0" indicator means "No payment adjustment rules for multiple procedures apply." Submitting your claim with modifier 51 could cause a payer to incorrectly reduce the allowable amount for the NMJ.

The "Frequency of Utilization" table in CPT's Appendix J includes guidelines for reporting 95937. NMJ testing for a final diagnosis of neuromuscular junction dysfunction has a maximum recommended study number of three.

"Code 95937 may be performed in conjunction with sensory and motor nerve conduction studies (NCS) of the same nerves, and are reimbursed separately," says Marianne Wink, RHIT, CPC, ACS-EM, with the University of Rochester Medical Center. Your neurosurgeon's documentation for each nerve tested should note characteristics of the test, including the rate of repetition of stimulations, and significant incremental or decremental response.