Billing and Coding: Autonomic Function Tests

This First Coast Billing and Coding Article for Local Coverage Determination
(LCD) L33609 Autonomic Function Tests provides billing and coding guidance for
frequency limitations as well as diagnosis limitations that support diagnosis
to procedure code automated denials. However, services performed for any given
diagnosis must meet all of the indications and limitations stated in the LCD,
the general requirements for medical necessity as stated in CMS payment policy
manuals, any and all existing CMS national coverage determinations, and all
Medicare payment rules.

Refer to the LCD for reasonable and necessary requirements and limitations.

The redetermination process may be utilized for consideration of services
performed outside of the reasonable and necessary requirements in the LCD.

**Coding Guidelines  **

The requirement for **CPT code 95921** Testing of autonomic nervous system
function; cardiovagal innervation (parasympathetic function), including 2 or
more of the following heart rate response to deep breathing with recorded R-R
interval, Valsalva ratio, and 30:15 ratio is that at least two of the tests
should be performed in order to bill this code. If only one test is performed,
modifier '52' should be appended to indicate that a reduced service was
provided.

The requirement for **CPT code 95922** Testing of autonomic nervous system
function; vasomotor adrenergic innervation (sympathetic adrenergic function),
including beat-to-beat blood pressure and R-R interval changes during Valsalva
maneuver and at least five minutes of passive tilt is that both a passive tilt
and the Valsalva maneuver be performed. If only one of the components is
performed, then modifier 52, reduced services, should be appended to code
95922.

**CPT code 95924** should be reported only when both the parasympathetic
function and vasomotor adrenergic function are tested together with at least 5
minutes of passive tilt.

Definitions of the terms included in code descriptors:

**Valsalva maneuver** : Any forced expiratory effort (strain) against a closed
airway, whether at the nose and mouth or at the glottis. This causes high
intrathoracic pressure that impedes venous return to the right atrium and,
therefore, can be used to study cardiovascular effects of raised peripheral
venous pressure and decreased cardiac filling and cardiac output, as well as,
post strain responses.

**Valsalva ratio** : The maximum heart rate divided by the lowest heart rate.
The subject performs a standardized Valsalva maneuver, and the derived heart
rate is analyzed.

**Quantitative sudomotor axon reflex test (QSART)** : An evaluation that uses
a quantitative noninvasive method to determine the integrity of the distal
postganglionic sympathetic nerve fibers in diabetic and other neuropathies
affecting autonomic nerves and in the progressive autonomic disorders. It uses
the stimulation of sympathetic nerve fibers to the sweat glands at standard
sites. The test is done optimally on one forearm site and three lower
extremity sites in order to determine the severity and distribution of the
sympathetic deficit.

**Notice:** It is not appropriate to bill Medicare for services that are not
covered (as described by the entire LCD) as if they are covered. When billing
for non-covered services, use the appropriate modifier.

**Documentation Requirements**

  1. All documentation must be maintained in the patient's medical record and made available to the contractor upon request.
  2. Every page of the record must be legible and include appropriate patient identification information (e.g., complete name, dates of service[s]). The documentation must include the legible signature of the physician or non-physician practitioner responsible for and providing the care to the patient.
  3. The submitted medical record must support the use of the selected ICD-10-CM code(s). The submitted CPT/HCPCS code must describe the service performed.
  4. General professional standards with FDA clearance apply for all equipment used in ANS testing. Providers may be asked to supply information on the equipment used to perform ANS studies to ensure all studies performed meet the requirements of the procedure.
  5. If the provider of the ANS studies is other than the ordering/referring physician/nonphysician practitioner, the provider of the service must maintain a copy of the test results and interpretation, along with copies of the ordering/referring physician/nonphysician practitioner's order for the studies.
  6. An order from the treating physician/nonphysician practitioner as required by CFR, Title 42, Volume 2, Chapter IV, Part 410.32(a) Ordering diagnosis tests. 

**Utilization Guidelines**

In accordance with CMS Ruling 95-1 (V), utilization of these services should
be consistent with locally acceptable standards of practice.

Compliance with the provisions in LCD L33609, Autonomic Function Tests may be
monitored and addressed through post payment data analysis and subsequent
medical review audits.