CPT code 95923 – Autonomic and sudomotor function testing

Key takeaways

CPT code 95923 covers sudomotor function testing not elsewhere classified, separate from cardiovagal testing (95921) and adrenergic testing (95922).

QSART, the thermoregulatory sweat test, sympathetic skin response and the silastic sweat imprint all report under this code. The code covers the testing session, not each individual test.

Medicare coverage follows LCD A54954 and A57651, and medical necessity needs a covered ICD-10-CM diagnosis such as E11.43 or G90.3.

Billing 95923 alongside 95924 triggers an unbundling denial, because 95924 already includes the sudomotor component.

Pabau attaches CPT code 95923 and its paired ICD-10-CM codes at the point of care, then routes the claim to a connected clearinghouse.

CPT code 95923: Official descriptor and procedure overview

CPT code 95923 describes testing of autonomic nervous system function, not elsewhere classified, of sudomotor function. The phrase “not elsewhere classified” carries weight here. It places 95923 in the residual category of the autonomic testing series 95921-95924. The code covers the sweat-output pathway, rather than the cardiovagal pathway that 95921 covers or the adrenergic pathway that 95922 covers. The American Medical Association maintains the CPT code set and is the authoritative source for the descriptor language.

Clinically, sudomotor testing evaluates postganglionic sympathetic cholinergic nerve fiber function by measuring sweat output at specified body sites. A normal result across all four sites effectively rules out small-fiber neuropathy affecting the autonomic pathway. An abnormal result supports the diagnosis and guides treatment for conditions such as diabetic autonomic neuropathy and Parkinson’s disease.

Which sudomotor tests the code covers

The code covers a family of sudomotor tests rather than a single procedure. Any of the following may be performed and reported under 95923, though QSART and the thermoregulatory sweat test are submitted most often. The table below summarizes each component.

QSART is the most widely used, because it produces quantitative, site-specific output that maps onto the documentation requirements in CMS LCDs. Some payers classify the thermoregulatory sweat test as investigational for certain indications, notably Aetna under CPB 0485. Those payers may deny a TST-only claim, so confirm the policy before the date of service.

How 95923 differs from 95921, 95922, and 95924

The autonomic testing series covers four different physiologic pathways, and billing the wrong one is a frequent denial trigger. Knowing where each code begins and ends matters as much as the documentation behind it.

95924 is a bundled code that already includes the sudomotor component. When a practice performs a full autonomic evaluation covering cardiovagal, adrenergic, and sudomotor testing in one session, 95924 is the code to submit. Billing 95923 alongside it generates an NCCI edit denial. Verify current bundling edits against the AAPC code reference before submitting.

The chart below maps each testing combination to the code the session supports.

Accepted ICD-10 diagnosis codes for sudomotor testing

Payers use the submitted ICD-10-CM code to determine medical necessity. A covered test paired with a non-covered diagnosis is denied. The following diagnoses are accepted under Medicare LCD A54954 and aligned commercial policies for autonomic sudomotor testing.

Every diagnosis above sits in the ICD-10-CM code set, and each MAC publishes its own accepted list. Use the CrossCoder crosswalk tool to verify which of them your MAC accepts for 95923. LCD appendices are updated periodically, so confirm the list against your MAC’s coverage database.

Medicare coverage rules and LCD for autonomic testing

Medicare coverage for CPT code 95923 is governed by Local Coverage Determinations A54954 and A57651, issued by the relevant Medicare Administrative Contractors. Checking the applicable LCD before the date of service prevents the most expensive outcome, which is performing the test and absorbing the write-off. The core LCD requirements are:

• The test must be ordered by the treating physician, not self-referred by the testing facility
• A covered ICD-10-CM diagnosis must be listed on the claim (see table above)
• The ordering physician’s clinical rationale must be documented in the medical record prior to testing
• Results must be interpreted and reported by a qualified physician; technical-component-only claims require modifier TC
• Frequency limitations apply. Repeat testing without a change in clinical status or treatment plan is commonly denied
• If Medicare is likely to deny and the patient has been informed, an Advance Beneficiary Notice must be signed before the service. Modifier GZ (no ABN obtained) and modifier GY (non-covered by statute) each change payment and patient liability

Commercial payers follow similar frameworks but are not bound by Medicare LCDs. Aetna’s Clinical Policy Bulletin 0485 covers autonomic and sudomotor testing and classifies certain approaches as investigational. BCBS North Dakota’s medical policy takes a comparable position on study indications. Both require prior authorization for most autonomic testing, so checking that requirement before scheduling reduces claim risk.

2025-2026 reimbursement rates for CPT code 95923

Medicare physician fee schedule rates for CPT code 95923 vary by geographic pricing locality. The figures below reflect the national non-facility rate. Facility rates are lower, because a hospital outpatient department or ambulatory surgery center bills separately for its overhead. Use the CMS Physician Fee Schedule lookup tool to confirm rates for your specific MAC and locality.

For exact 2026 values, use the FastRVU 2026 RVU lookup tool, which pulls directly from CMS data files. Commercial rates vary widely by contract, so treat the Medicare rate as a floor for negotiation rather than a ceiling. Practice management software like Pabau closes the loop after that. Its claims management software sends 837P transactions to a connected clearinghouse and returns ERAs, so billing staff reconcile payments without switching between systems.

Modifiers used with 95923

Modifier usage is where many 95923 claims break down. The correct modifier depends on what was performed, who performed it, and whether the service overlaps with another code billed on the same date.

Modifier rules change annually. NCCI edit pairs in this family have shifted across recent code cycles. Check your MAC’s current guidance before submitting a claim that uses modifier 59 on the 95921-95924 series.

Documentation requirements to support a 95923 claim

Documentation carries more weight than any other variable in 95923 billing. A correctly coded, correctly authorized claim is still denied when the medical record does not support medical necessity at audit. Build the requirements into the clinical workflow rather than assembling them during an appeal. The required elements are:

• Ordering physician’s clinical rationale: The medical record must document the symptom pattern or established diagnosis that prompted the test. A referral form carrying only a code does not qualify
• Test report with site-specific results: For QSART, the report must carry all four standard sites. Those are the forearm, proximal leg, distal leg and foot. A single-site result does not satisfy the protocol
• Physician interpretation: A qualified physician must sign and date the interpretation. A technician-only report with no physician attestation is a denial trigger
• Covered diagnosis in the chart: The ICD-10-CM code on the claim must match a diagnosis in the clinical notes. That diagnosis must be documented on or before the date of service
• Frequency documentation: On a repeat study, the chart must document why further testing is medically necessary. A change in clinical status, a new treatment, or disease progression all qualify
• ABN when applicable: If Medicare is likely to deny, the signed ABN must be dated before the test is performed

A superbill captures the CPT code, the linked ICD-10-CM codes, and the performing provider in one structured form. That cuts transcription errors between the note and the claim. Clinical note templates can be configured to prompt for each element at the point of documentation, so billers receive complete information without chasing records.

Common reasons 95923 claims are denied

Most 95923 denials fall into a predictable set of patterns. Recognizing them before submission costs far less than working the denial afterward. The table below lists the most frequent denial reasons and the corrective action for each.

Reading the CARC reason codes returned on the remittance tells billing staff which of these patterns is driving the rejection. Pabau surfaces that remittance data inside the billing module, so the denial reason, the original claim, and the patient record sit in one place.

Bundling rules: What cannot be billed on the same date

Bundling violations account for a large share of 95923 denials. The NCCI edits for the autonomic testing series are specific about which codes can and cannot be billed together. Check the current edits in the CMS NCCI policy manual before finalizing a multi-code claim.

The remittance returned after a bundling denial usually carries CARC code 97. That code means the service is included in payment for another service on the same date. Treat that code as a prompt to check which other code on the claim absorbed 95923.

How Pabau keeps autonomic testing claims clean

In most neurology practices a 95923 claim crosses three systems before it reaches a payer. The technician’s report sits in one place, the physician’s interpretation in another, and the biller retypes the code and the diagnosis into a claim form. Each handoff is a chance for the ICD-10-CM code on the claim to drift from the one documented in the chart.

Pabau keeps those pieces in one record. A clinical note template can prompt for the ordering physician’s rationale, the site-specific results, and the signed interpretation. The elements an LCD audit asks for are then captured during the visit. The CPT and ICD-10-CM codes attach to that same encounter rather than to a separate billing sheet.

From there the claim goes to the clearinghouse, and the remittance comes back against the original claim and the patient record. When a CARC 97 bundling denial arrives, the biller can see which code absorbed 95923 without opening a second system or calling the clinical team.

See how Pabau streamlines autonomic testing claims

Attach CPT code 95923 and paired ICD-10 codes at the point of care, route claims through a connected clearinghouse, and track ERAs without switching systems. Book a demo to see the billing workflow in action.

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Conclusion

CPT code 95923 is well defined, and its denial rate tracks the documentation, the diagnosis pairing, and the same-date bundling rules behind it. Get the QSART site count into the report, pick an ICD-10-CM code the LCD accepts, and recognize the sessions that belong to 95924. Those three habits move first-pass payment further than any appeal workflow.

Build those checks into the visit rather than the appeal, and the write-offs stop before a claim leaves the practice. Book a demo to see how Pabau connects the autonomic test report, the coded claim, and the remittance in one record.

Continue your research

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