Part B Insider (Multispecialty) Coding Alert

Counting nerves correctly leads to fewer repays.

Even though your physician may --and often will -- repetitively stimulate a single nerve during neuromuscular junction (NMJ) testing, you've got to code based on separate and distinct nerves, not the number of stimulations performed on each nerve, experts say.

For NMJ testing, report 95937 (Neuromuscular junction testing...). Repetitive stimulation studies identify and differentiate disorders of the NMJ, such as myasthenia gravis.

The code description includes the term "each nerve," and that's where trouble begins. You should report 95937 as a single line item with the total number of separate and distinct nerves tested reported in box 24G or its electronic equivalent.

Example: Suppose the doctor 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. You should report a single line item of 95937 with "3" in the units field.

If the doctor performs a procedure on the right and left upper extremities, then it's bilateral, right? Not so fast. Code 95937 should not be billed as bilateral because it carries a "0" bilateral status indicator in the Medicare Physician Fee Schedule, says Lynn McCormack, CPC, with HCA Physician Services in Las Vegas. The "0" indicator means "150 percent payment adjustment for bilateral procedures does not apply." Even though your doctor may test the ulnar nerve on both the right and left upper extremities, CMS does not consider the testing bilateral.

Similarly, you should not 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." Use of the 51 modifier could cause a payer to incorrectly reduce the allowable amount for the NMJ.

In appendix J of the CPT manual,the "Frequency of Utilization" table includes 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. The documentation for each nerve tested should note characteristics of the test, including the rate of repetition of stimulations, and significant incremental or decremental response.