Electrical nerve stimulation is an accepted modality for assessing a patient's
suitability for ongoing treatment with a transcutaneous or an implanted nerve
stimulator.

Accordingly, program payment may be made for the following techniques when
used to determine the potential therapeutic usefulness of an electrical nerve
stimulator:

**A. Transcutaneous Electrical Nerve Stimulation (TENS)**

This technique involves attachment of a transcutaneous nerve stimulator to the
surface of the skin over the peripheral nerve to be stimulated. It is used by
the patient on a trial basis and its effectiveness in modulating pain is
monitored by the physician, or physical therapist. Generally, the physician or
physical therapist is able to determine whether the patient is likely to
derive a significant therapeutic benefit from continuous use of a
transcutaneous stimulator within a trial period of 1 month; in a few cases
this determination may take longer to make. Document the medical necessity for
such services which are furnished beyond the first month. (See
[160.13](https://www.cms.gov/medicare-coverage-database/details/ncd-
details.aspx?NCDId=151&ncdver=1&DocID=160.13&bc=gAAAAAgAAAAA&) for an
explanation of coverage of medically necessary supplies for the effective use
of TENS.)

If TENS significantly alleviates pain, it may be considered as primary
treatment; if it produces no relief or greater discomfort than the original
pain electrical nerve stimulation therapy is ruled out. However, where TENS
produces incomplete relief, further evaluation with percutaneous electrical
nerve stimulation may be considered to determine whether an implanted
peripheral nerve stimulator would provide significant relief from pain.

Usually, the physician or physical therapist providing the services will
furnish the equipment necessary for assessment. Where the physician or
physical therapist advises the patient to rent the TENS from a supplier during
the trial period rather than supplying it himself/herself, program payment may
be made for rental of the TENS as well as for the services of the physician or
physical therapist who is evaluating its use. However, the combined program
payment which is made for the physician's or physical therapist's services and
the rental of the stimulator from a supplier should not exceed the amount
which would be payable for the total service, including the stimulator,
furnished by the physician or physical therapist alone.

**B. Percutaneous Electrical Nerve Stimulation (PENS)**

This diagnostic procedure which involves stimulation of peripheral nerves by a
needle electrode inserted through the skin is performed only in a physician's
office, clinic, or hospital outpatient department. Therefore, it is covered
only when performed by a physician or incident to physician's service. If pain
is effectively controlled by percutaneous stimulation, implantation of
electrodes is warranted.

As in the case of TENS (described in subsection A), generally the physician
should be able to determine whether the patient is likely to derive a
significant therapeutic benefit from continuing use of an implanted nerve
stimulator within a trial period of 1 month. In a few cases, this
determination may take longer to make. The medical necessity for such
diagnostic services which are furnished beyond the first month must be
documented.

**NOTE:** Electrical nerve stimulators do not prevent pain but only alleviate
pain as it occurs. A patient can be taught how to employ the stimulator, and
once this is done, can use it safely and effectively without direct physician
supervision. Consequently, it is inappropriate for a patient to visit his/her
physician, physical therapist, or an outpatient clinic on a continuing basis
for treatment of pain with electrical nerve stimulation. Once it is determined
that electrical nerve stimulation should be continued as therapy and the
patient has been trained to use the stimulator, it is expected that a
stimulator will be implanted or the patient will employ the TENS on a
continual basis in his/her home. Electrical nerve stimulation treatments
furnished by a physician in his/her office, by a physical therapist or
outpatient clinic are excluded from coverage by 1862(a)(1) of the Act. (See
[160.7](https://www.cms.gov/medicare-coverage-database/details/ncd-
details.aspx?NCDId=240&ncdver=1&DocID=160.7&kq=true&bc=gAAAAAgAAAAA&) for an
explanation of coverage of the therapeutic use of implanted peripheral nerve
stimulators under the prosthetic devices benefit.) See
[160.27](https://www.cms.gov/medicare-coverage-database/details/ncd-
details.aspx?NCDId=354&ncdver=1&DocID=160.27&kq=true&kq=true&bc=gAAAAAgAAAAA&)
for an explanation of coverage of the therapeutic use of TENS under the
durable medical equipment benefit.