Orthopedic Coding Alert

Master evoked potential base codes, then move on to specifics.

Patients presenting for an evoked potential (EP) study present challenges beyond mere CPT^® code assignment.

Reason: EP study codes are broken over several “base” codes, and finding the proper code each time takes foresight and knowledge.

Not to worry, as we picked the brain of Amy C. Pritchett, BSHA, CCS, CPMA, CPC-I, CPC, CDEO, CANPC, CASCC, CEDC, CRC, CMRS, CMPM, CDMP, C-AHI, AIHC-Approved ICD-10-CM/PCS Trainer, manager of facility coding services at Altegra Health in Los Angeles, to talk EP study coding. Here’s what she had to say:

Q: How and when would you code for a short-latency EP study?

A: If the notes indicate a short-latency EP study, Pritchett confirms you’d report one of the following codes:

• 95925 — Short-latency somatosensory evoked potential study, stimulation of any/all peripheral nerves or skin sites, recording from the central nervous system; in upper limbs 
• 95926 — … in lower limbs 
• 95938 — … in upper and lower limbs
• 95927 — … in the trunk or head.

The short-latency EP studies represent the stimulation of any and all peripheral nerves and skin sites in the area indicated within the code descriptor. The codes also include recording from the central nervous system, Pritchett explains.

So if the encounter notes indicate that the provider performed a short-latency EP study on a patient’s trunk, you’d report 95927 for the encounter.

Q: Who might need a short-latency EP study?

A:  Patients that suffer from the following conditions might require a short-latency EP study, Pritchett says:

• Myasthenia gravis,
• carpal tunnel syndrome and/or ulnar nerve entrapment,
• spinal cord or head injuries,
• cervical spondylotic myeloradiculopathy,
• thoracic outlet syndrome,
• metabolic disorders, and
• amyotrophic lateral sclerosis (ALS).

Note: This is not a comprehensive, or approved, list of conditions that warrant a short-latency EP; patients with these ailments, however, could be candidates for a 92925-95927 service.

Q: How and when would you code for a central motor EP study?

A: If the notes indicate a central motor EP study, Pritchett confirms you’d report one of the following codes:

• 95928 — Central motor evoked potential study (transcranial motor stimulation); upper limbs
• 95929 — … lower limbs 
• 95939 — … in upper and lower limbs.

During a central motor EP study, “the provider performs a central motor evoked potential study by transcranially stimulating the motor cortex by applying a very mild electric current to the scalp,” explains Pritchett. In this procedure, the ultimate goal is to evaluate the motor pathways that supply the upper or lower limb muscles — or both, depending on encounter specifics.

So if notes indicate that the provider performed a central motor EP study in a patient’s lower limbs, you’d report 95929 for the encounter.

Q: Who might need a central motor EP study?

A: According to Pritchett, one of the following conditions might trigger a central motor EP study:

• Temporal bone lesion,
• malignant neoplasm of spinal meninges.

Note: As stated earlier, this is not an exhaustive or approved list for these types of studies. Patients with these types of conditions, however, are candidates for a central motor EP study.