Need help choosing the right code?
Ask CasePilot about procedures, modifiers, bundling, and coding guidance.
Try CasePilot© Copyright 2026 American Medical Association. All rights reserved.
Short-latency somatosensory evoked potential (SEP) studies are diagnostic procedures that assess the function of the somatosensory pathways in the central nervous system. These studies measure the electrical signals generated by afferent peripheral nerve fibers in response to sensory stimuli. The term "short-latency" refers to the specific portion of the SEP waveform that exhibits the shortest delay time following stimulation, which is critical for evaluating the integrity of the neural pathways involved in sensory processing. The latency time can vary based on the specific nerve being tested; for instance, short-latency SEPs for upper extremity nerves occur within 25 milliseconds of stimulation, while those for the tibial nerve are recorded within 50 milliseconds. An abnormal result in these tests may indicate dysfunction within the somatosensory pathways, which can be indicative of various neurological conditions. The procedure involves the application of electrical stimulation to selected peripheral nerves or skin sites, with electrodes strategically placed to capture the resulting electrical activity in the central nervous system. This comprehensive evaluation is essential for diagnosing and understanding sensory pathway disorders.
© Copyright 2026 Coding Ahead. All rights reserved.
Short-latency somatosensory evoked potential studies are performed for various clinical indications, particularly when there is a need to evaluate the integrity of the somatosensory pathways. The following conditions may warrant this procedure:
The procedure for conducting a short-latency somatosensory evoked potential study involves several key steps to ensure accurate measurement and recording of the electrical signals generated by peripheral nerves. The following procedural steps are typically followed:
After the completion of the short-latency somatosensory evoked potential study, patients may be monitored briefly to ensure there are no immediate adverse effects from the electrical stimulation. Typically, there are no significant post-procedure care requirements, and patients can resume their normal activities shortly after the study. The physician will provide the patient with the results of the study, which may include recommendations for further evaluation or treatment based on the findings. It is essential for the physician to discuss the implications of the results with the patient, particularly if any abnormalities are detected that may require additional diagnostic or therapeutic interventions.
| Short Descr | SOMATOSENSORY TESTING | Medium Descr | SHORT-LATENCY SOMATOSENS EP STD TRNK/HEAD | Long Descr | Short-latency somatosensory evoked potential study, stimulation of any/all peripheral nerves or skin sites, recording from the central nervous system; in the trunk or head | Status Code | Active Code | Global Days | XXX - Global Concept Does Not Apply | PC/TC Indicator (26, TC) | 1 - Diagnostic Tests for Radiology Services | Multiple Procedures (51) | 0 - No payment adjustment rules for multiple procedures apply. | Bilateral Surgery (50) | 0 - 150% payment adjustment for bilateral procedures does NOT apply. | Physician Supervisions | 09 - Concept does not apply. | Assistant Surgeon (80, 82) | 0 - Payment restriction for assistants at surgery applies to this procedure... | Co-Surgeons (62) | 0 - Co-surgeons not permitted for this procedure. | Team Surgery (66) | 0 - Team surgeons not permitted for this procedure. | Diagnostic Imaging Family | 99 - Concept Does Not Apply | APC Status Indicator | Procedure or Service, Not Discounted when Multiple | Type of Service (TOS) | 1 - Medical Care | Berenson-Eggers TOS (BETOS) | T2D - Other tests - other | MUE | 1 | CCS Clinical Classification | 7 - Other diagnostic nervous system procedures |
This is a primary code that can be used with these additional add-on codes.
| 95940 | Addon Code Resequenced Code MPFS Status: Active Code APC N Continuous intraoperative neurophysiology monitoring in the operating room, one on one monitoring requiring personal attendance, each 15 minutes (List separately in addition to code for primary procedure) | 95941 | Addon Code Resequenced Code MPFS Status: Not valid for Medicare purposes APC N Continuous intraoperative neurophysiology monitoring, from outside the operating room (remote or nearby) or for monitoring of more than one case while in the operating room, per hour (List separately in addition to code for primary procedure) | G0453 | Add-on Code Medicare Coverage: Carrier Priced MPFS Status: Active Code APC N Continuous intraoperative neurophysiology monitoring, from outside the operating room (remote or nearby), per patient, (attention directed exclusively to one patient) each 15 minutes (list in addition to primary procedure) |
| 26 | Professional component: certain procedures are a combination of a physician or other qualified health care professional component and a technical component. when the physician or other qualified health care professional component is reported separately, the service may be identified by adding modifier 26 to the usual procedure number. | 59 | Distinct procedural service: under certain circumstances, it may be necessary to indicate that a procedure or service was distinct or independent from other non-e/m services performed on the same day. modifier 59 is used to identify procedures/services, other than e/m services, that are not normally reported together, but are appropriate under the circumstances. documentation must support a different session, different procedure or surgery, different site or organ system, separate incision/excision, separate lesion, or separate injury (or area of injury in extensive injuries) not ordinarily encountered or performed on the same day by the same individual. however, when another already established modifier is appropriate it should be used rather than modifier 59. only if no more descriptive modifier is available, and the use of modifier 59 best explains the circumstances, should modifier 59 be used. note: modifier 59 should not be appended to an e/m service. to report a separate and distinct e/m service with a non-e/m service performed on the same date, see modifier 25. | XS | Separate structure, a service that is distinct because it was performed on a separate organ/structure | 76 | Repeat procedure or service by same physician or other qualified health care professional: it may be necessary to indicate that a procedure or service was repeated by the same physician or other qualified health care professional subsequent to the original procedure or service. this circumstance may be reported by adding modifier 76 to the repeated procedure or service. note: this modifier should not be appended to an e/m service. | GZ | Item or service expected to be denied as not reasonable and necessary | 52 | Reduced services: under certain circumstances a service or procedure is partially reduced or eliminated at the discretion of the physician or other qualified health care professional. under these circumstances the service provided can be identified by its usual procedure number and the addition of modifier 52, signifying that the service is reduced. this provides a means of reporting reduced services without disturbing the identification of the basic service. note: for hospital outpatient reporting of a previously scheduled procedure/service that is partially reduced or cancelled as a result of extenuating circumstances or those that threaten the well-being of the patient prior to or after administration of anesthesia, see modifiers 73 and 74 (see modifiers approved for asc hospital outpatient use). | GC | This service has been performed in part by a resident under the direction of a teaching physician | SA | Nurse practitioner rendering service in collaboration with a physician | TC | Technical component; under certain circumstances, a charge may be made for the technical component alone; under those circumstances the technical component charge is identified by adding modifier 'tc' to the usual procedure number; technical component charges are institutional charges and not billed separately by physicians; however, portable x-ray suppliers only bill for technical component and should utilize modifier tc; the charge data from portable x-ray suppliers will then be used to build customary and prevailing profiles | XU | Unusual non-overlapping service, the use of a service that is distinct because it does not overlap usual components of the main service |
|
Date
|
Action
|
Notes
|
|---|---|---|
| 2021-01-01 | Note | Guidelines changed. |
| 1996-01-01 | Added | First appearance in code book in 1996. |
Get instant expert-level medical coding assistance.