Autonomic Nerve Function Testing

Coverage Summary

This policy (Medical Coverage Policy: 0506) addresses Autonomic Nerve Function Testing (subject: Autonomic Nerve Function Testing) and defines Cigna's medical necessity coverage for sudomotor, cardiovagal, adrenergic, and combined autonomic testing. Status: MODIFIED; Last review: 2026-02-15. The policy summarizes covered indications and lists that CPT codes 95921, 95922, 95923, and 95924 are considered medically necessary when the listed criteria are met.

Medical-Necessity Criteria

Medically Necessary Indications

Autonomic nerve function testing is considered medically necessary to evaluate autonomic nerve function and aid in the diagnosis of ANY of the following conditions:

Medically necessary indications

Distal small fiber neuropathy
Postural tachycardia syndrome (POTS)
Reflex sympathetic dystrophy (e.g., sympathetically maintained pain, causalgia)
Recurrent, unexplained syncope
Progressive autonomic neuropathies - Diabetic autonomic neuropathy
Progressive autonomic neuropathies - Amyloid neuropathy
Progressive autonomic neuropathies - Sjogren's syndrome
Progressive autonomic neuropathies - Idiopathic neuropathy
Progressive autonomic neuropathies - Pure autonomic failure
Progressive autonomic neuropathies - Multiple system atrophy (Shy-Drager syndrome)

Not Covered

Autonomic nerve function testing to aid in the diagnosis of ANY other condition is not covered or reimbursable.

Not covered diagnoses: All other conditions or diagnoses not listed in the medically necessary indications above

CPT-specific Medical Necessity Statements

Considered Medically Necessary when criteria in the applicable policy statements listed above are met:

CPT-specific statements

CPT 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
CPT 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 5 minutes of passive tilt
CPT 95923: Testing of autonomic nervous system function; sudomotor, including 1 or more of the following: quantitative sudomotor axon reflex test (QSART), silastic sweat imprint, thermoregulatory sweat test, and changes in sympathetic skin potential
CPT 95924: Testing of autonomic nervous system function; combined parasympathetic and sympathetic adrenergic function testing with at least 5 minutes of passive tilt

Noncoverage - Portable Automated Autonomic Nerve Function Testing Devices

Covered when ALL of the following are met: (policy removed statement — reflected in revision history as removal)

Portable automated devices noncoverage removed: Policy statement for portable, automated autonomic nerve function testing devices was removed.

Indicates noncoverage position revised in 2026 annual review; see revision history (Annual Review Date 2/15/2026)

Other Noncoverage / Revised Noncoverage Statement (2024)

Noncoverage statements revised previously.

2024 revision note: Noncoverage policy statement revised on Annual Review Date 2/15/2024.

Exact previous wording not present in this part of the document.

Clinical Policy Statements

No clinical policy statement changes noted for the 2/15/2025 annual review.

2025 clinical policy statements: No clinical policy statement changes for Annual Review Date 2/15/2025.

Coding

Covered CPT codes (when criteria met)CPTCovered

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
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 5 minutes of passive tilt
95923	Testing of autonomic nervous system function; sudomotor, including 1 or more of the following: QSART, silastic sweat imprint, thermoregulatory sweat test, and changes in sympathetic skin potential
95924	Testing of autonomic nervous system function; combined parasympathetic and sympathetic adrenergic function testing with at least 5 minutes of passive tilt

Not covered ICD-10-CM diagnosis codes (all other codes)ICD-10Not Covered

All other codes

ICD-10-CM Diagnosis Codes not listed as covered are not covered or reimbursable

Listed ICD-10-CM diagnosis codes referenced as covered/appropriateICD-10

A50.43	Late congenital syphilitic polyneuropathy
A52.15	Late syphilitic neuropathy
E09.40	Drug or chemical induced diabetes mellitus with neurological complications with diabetic neuropathy, unspecified
E09.41	Drug or chemical induced diabetes mellitus with neurological complications with diabetic mononeuropathy
E09.42	Drug or chemical induced diabetes mellitus with neurological complications with diabetic polyneuropathy
E09.43	Drug or chemical induced diabetes mellitus with neurological complications with diabetic autonomic (poly)neuropathy
E09.49	Drug or chemical induced diabetes mellitus with neurological complications with other diabetic neurological complication
E10.40	Type 1 diabetes mellitus with diabetic neuropathy, unspecified
E10.41	Type 1 diabetes mellitus with diabetic mononeuropathy
E10.42	Type 1 diabetes mellitus with diabetic polyneuropathy

1–10 of 75

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Provider Actions

Documentation Required

Submit supporting diagnosis codes

Claims must be submitted with covered diagnosis and/or procedure codes. Services billed for conditions not accompanied by covered codes under this policy will be denied as not covered.

Prior Authorization

Coverage requires meeting clinical indications

CPT codes 95921–95924 are considered medically necessary only when the listed covered indications are present. Testing for any other conditions is not covered and may require prior authorization or may be denied.

95921
95922
95923
95924

Background, Evidence & Definitions

The autonomic nervous system regulates internal organ functions including blood pressure, heart rate, temperature, metabolism, and sweating through parasympathetic and sympathetic branches; disorders may be structural (e.g., diabetic autonomic neuropathy, multiple system atrophy) or functional (e.g., POTS) and can affect many organ systems.

Autonomic testing is grouped into sudomotor (sweat-related), cardiovagal (parasympathetic heart rate responses), and adrenergic/vasomotor (sympathetic blood pressure/beat-to-beat responses) evaluations. Common sudomotor tests include the quantitative sudomotor axon reflex test (QSART), thermoregulatory sweat test (TST), sympathetic skin response (SSR), silastic sweat imprint, QDIRT (quantitative direct and indirect reflex test) and QPART (quantitative pilomotor axon reflex test).

Cardiovagal testing assesses heart rate variation with maneuvers such as deep breathing, the Valsalva ratio, and posture changes. Vasomotor adrenergic testing evaluates continuous beat-to-beat blood pressure and heart rate responses during Valsalva maneuvers and at least 5 minutes of passive tilt; combined testing may use a tilt table for at least 5 minutes to differentiate parasympathetic and sympathetic cardiovascular function.

Comprehensive autonomic testing is typically performed in a dedicated autonomic testing laboratory by specialists and includes ECG, respiratory and blood pressure monitoring, and may include tilt table testing; interpretation should consider confounding factors (medications, room conditions, patient factors) and be performed by qualified personnel.

Automated or portable 'ANS testing' devices (e.g., electrochemical skin conductance or moisture-based systems and other marketed automated technologies) have limitations: many do not provide beat-to-beat recordings, do not include physician interpretation, may not evaluate integrity of sudomotor axons, have inconsistencies in technique and normative values, and have not been validated sufficiently in the literature; professional society guidance advises caution and recommends testing in a clinical autonomic laboratory with expert interpretation.

Medicare Determinations

Number	Name	Type	Effective Date
{"text":"L33609","status":""},{"text":"Autonomic Function Tests","status":""},{"text":"LCD","status":""},{"text":"2021-01-07","status":""}
{"text":"L36236","status":""},{"text":"Autonomic Function Testing","status":""},{"text":"LCD","status":""},{"text":"2019-09-12","status":""}
{"text":"L35395","status":""},{"text":"Autonomic Function Tests","status":""},{"text":"LCD","status":""},{"text":"2019-11-14","status":""}
{"text":"L35124","status":""},{"text":"Autonomic Function Testing","status":""},{"text":"LCD","status":""},{"text":"2025-10-30","status":""}

Revision History

2/15/2026removedLatest

Removed policy statement for portable, automated autonomic nerve function testing devices.

2/15/2026removedLatest

Removed policy statement for portable, automated autonomic nerve function testing devices.

2/15/2025clarified

Source	Summary/Reference
Consensus statement
Cheshire et al., 2021 AAS/AAN/IFCN consensus endorses comprehensive autonomic test battery, recommends testing in clinical autonomic lab and cautions against automated devices without physician interpretation.
AANEM position
AANEM 2023/2025 recommends specific tests (QSART, TST, silastic imprint, SSR, cardiovagal and adrenergic measures) and physician qualifications for performance and interpretation.
FDA device clearances
Multiple devices cleared via 510(k) including Finapres NOVA K173916, Sudoscan K100233, Q-Sweat K992874 (FDA 510(k) database listings).
References included in this part
Selected references: Arnold et al. 2021; Wang et al. 2008; Wenning et al. 2022; Kittleson et al. 2023; Zhao et al. 2022 (see References section).

Term	Definition
QSART
The QSART involves stimulation of the sympathetic nerve fibers using iontophoresis of acetylcholine and then measuring an evoked sweat response; it evaluates the functional status of postganglionic sympathetic axons.
TST
The thermoregulatory sweat test assesses sympathetic nerves supplying the skin using a color indicator and heat cabinet to evaluate pre- and postganglionic pathways and documents sweat distribution.
SSR
The sympathetic skin response measures a change in skin resistance following electrical stimulation to provide an index of sweat production (recorded as present or absent in hand and foot).