01-164 Autonomic Function Testing Notification of Medical Review

Noridian Healthcare Solutions, LLC (Noridian), as the Supplemental Medical Review Contractor (SMRC) for the Centers of Medicare and Medicaid Services (CMS), is conducting post-payment review of claims for Medicare Part B for autonomic function testing billed on dates of service from January 1, 2024 through December 31, 2025. This notification includes the reasons for the review, documentation that will be requested in the Additional Documentation Request (ADR) letter, and resources providers/suppliers may wish to consult when submitting claims.

Background

The autonomic nervous system (ANS) controls and regulates the body’s involuntary functions through the sympathetic and parasympathetic nervous systems, including cardiovascular, respiratory, gastrointestinal, sudomotor, and genitourinary functions. Autonomic disorders may involve either reduced or excessive autonomic activity. They may be congenital or acquired and may affect a single organ system or be generalized. Autonomic failure is associated with increased morbidity and mortality, particularly due to complications such as orthostatic hypotension and risk of falls. Although symptoms can be nonspecific, autonomic dysfunction can be clinically diagnosed using standardized autonomic testing.

Autonomic function testing (AFT) evaluates cardiovagal innervation (parasympathetic cardiac), vasomotor adrenergic innervation (blood pressure and heart rate), and sudomotor (sweat gland) function. Tests include heart rate and blood pressure responses to maneuvers such as deep breathing, Valsalva, standing, tilt-table testing, and sweat assessments (quantitative sudomotor axon reflex test (QSART), and the thermoregulatory sweat test (TST), and sweat imprints). Proper selection and interpretation of these tests support diagnostic specificity, guide clinical management, and may be used to monitor disease progression or treatment response.

Medicare Part B covers AFT for specific clinical indications and does not cover testing performed solely for screening without symptoms.

In October 2025, Noridian Healthcare Solutions, LLC, as the SMRC, completed research and data analysis on AFT and identified a potential vulnerability related to claims billed with modifier 59 (distinct procedural service). Modifier 59 is permitted when AFT codes provided the services are clinically distinct, such as occurring at different anatomical sites or encounters.

Reason for Review

The SMRC is tasked to perform data analysis and conduct medical record reviews on claims billed with current procedural terminology (CPT) codes 95921-95924 billed with date of service January 1, 2024, through December 31, 2025.

The SMRC will conduct medical record reviews in accordance with applicable waivers/flexibilities/statutory, regulatory, and sub-regulatory guidance.

Claim Sample Detail

CPT Description
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: quantitative sudomotor axon reflex test (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

Access related project details below.

Documentation Requirements

Below is a list of specific documentation requirements that will be included in each ADR to obtain the necessary documentation to perform the review.

Providers/suppliers are requested to submit each of the Documentation Requirements outlined below, if and as applicable to the claim on review.

  1. Please Note: The ordering or referring physician is responsible for forwarding appropriate clinical data for the autonomic function test to the diagnostic testing facility and confirm all medical necessity criteria have been met
  2. Physician/Non-Physician Practitioner (NPP) order or evidence of intent to order the autonomic function test
  3. Clinical documentation supporting the diagnosis code(s) for the autonomic function test ordered, including relevant progress notes or history and physical documentation for the date of service under review
  4. Results and interpretation of the Autonomic Nervous System (ANS) test ordered for the date of service under review, including cardiovagal, vasomotor adrenergic, and/or sudomotor function testing
  5. Previous autonomic function test results and reports within the last two years, including standard testing, supporting the date of service under review, if applicable
  6. Clinical progress notes from the ordering and/or referring provider that support the medical necessity of the autonomic function test, including the covered indication and relevant signs and symptoms
  7. Documentation supporting the medical necessity of a repeat test, including changes in the patient’s clinical status and/or response to therapeutic intervention
  8. Documentation to support the code(s) and modifier(s) billed
  9. Providers and/or suppliers are encouraged to review the documentation prior to submission, to ensure that signature information is available. Please include a signature log or signature attestation for any missing or illegible signature within the medical record
  10. If an electronic health record is utilized, include your facility’s process of how the electronic signature is created. Include an example of how the electronic signature displays once signed by the physician.
  11. Advance Beneficiary Notice of Non-Coverage (ABN)/Notice of Medicare Non-Coverage (NOMNC)
  12. Medical record documentation to support national and local requirements
  13. Any other supporting/pertinent documentation
  14. If medical record documentation is submitted via esMD Beneficiary identification, date of service, and provider of the service should be clearly identified on each page of the submitted documentation

References

Social Security Act (SSA), Title XVIII

  • §1815(a) Payment to Providers of Services
  • §1833(e) Payment of Benefits
  • §1861(s)(2)(C) Medical and Other Health Services
  • §1862(a)(1)(A) Exclusion from Coverage and Medicare as a Secondary Payer
  • §1862(a)(7) Exclusions from Coverage and Medicare
  • §1879(a)(1) Limitation on Liability of Beneficiary where Medicare Claims are Disallowed
  • §1893(b) Medicare Integrity Program

42 Code of Federal Regulations (CFR)

  • §410.20 Physicians’ Services
  • §410.32 Diagnostic X-ray test, diagnostic laboratory test, and other diagnostic test: conditions
  • §410.33 Independent Diagnostic Testing Facility
  • §411.15(k)(1) Particular services excluded from coverage
  • §413.65 Requirements for a determination that a facility or an organization has a provider-based status
  • §414.50 Physician or other supplier billing for diagnostic tests performed or interpreted by a physician who does not share a practice with the billing physician or other supplier
  • §424.5(a)(6) Basic Conditions

Internet Only Manual (IOM), Publication (Pub.) 100-02, Medicare Benefit Policy Manual (MBPM)

  • Chapter 15, §80 Requirements for Diagnostic X-Ray, Diagnostic Laboratory, and Other Diagnostic Tests
  • Ch. 15, §80.6.1 Definitions
  • Ch 16, §10 General Exclusions from Coverage
  • Ch 16, §20 Services Not Reasonable and Necessary

IOM, Pub. 100-04, Medicare Claims Processing Manual (MCPM)

  • Ch. 1, General Billing Requirements
  • Ch. 23, §20 National Correct Coding Initiative (NCCI)
  • Ch. 30, §50 Advance Beneficiary Notice of Non-coverage (ABN)
  • Ch. 35, Independent Diagnostic Testing Facility (IDTF)

IOM, Pub. 100-08, Medicare Program Integrity Manual (MPIM)

  • Ch. 3, Verifying Potential Errors and Taking Corrective Actions
  • Ch. 13, §13.5.4 Reasonable and Necessary Provisions in an LCDs

CMS Coding Policies

  • National Correct Coding Initiative (NCCI) Policy Manual for Medicare Services. Effective 2024 and 2025

Local Coverage Determination (LCD)

  • L33609 Autonomic Function Tests
  • L35124 Autonomic Function Tests
  • L35395 Autonomic Function Tests
  • L36236 Autonomic Function Tests

Local Coverage Article (LCA)

  • A54954 Billing and Coding: Autonomic Function Testing
  • A57024 Billing and Coding: Autonomic Function Testing
  • A57551 Billing and Coding: Autonomic Function Testing
  • A57651 Billing and Coding: Autonomic Function Testing

Other

Last Updated Jun 18, 2026