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HCPCS A4594 · Level II · A code

A4594: Neuromodulation stimulator system, adjunct to rehabilitation therapy regime, HCPCS Level II A code

Compiled from CMS files by the QuickIntell RCM Editorial Team · Data effective · Method: reference methodology · Report a data correction

Data currency: HCPCS Level II file: October 2026 (effective October 1, 2026); PFS relative value file: RVU26D, released August 26, 2026 (effective October 1, 2026); DMEPOS fee schedule: DME26-D (October 2026) (effective October 1, 2026); NCCI MUE tables: 2026 Q4 (effective October 1, 2026); NCCI PTP edits: v323r0 (2026 Q4) (effective October 1, 2026); OPPS Addendum B: October 2026 (effective October 1, 2026). Next CMS release: January 1, 2027 (quarterly update) for the HCPCS Level II file and DMEPOS fee schedule and NCCI MUE tables and NCCI PTP edits and OPPS Addendum B; RVU27A with the CY2027 PFS final rule, effective January 1, 2027 for the PFS relative value file.

Key facts for A4594

Medicare payment
$3,095.12
DMEPOS non-rural state fees (NU)
Coverage code
C
carrier judgment, so the Medicare contractor decides coverage
DME supplier MUE
1
MAI 2
OPPS status
SI E1
Non-allowed item or service
NCCI PTP pairs
0
practitioner file
LCDs and articles
0 / 0

TL;DR

HCPCS Level II A4594 reads "Neuromodulation stimulator system, adjunct to rehabilitation therapy regime, mouthpiece each" in the October 2026 file; it dates from 2024. DMEPOS fees for A4594, a IN (inexpensive and other routinely purchased items) item, run NU (purchased, new) $3,095.12 in every contiguous state (floor $2,630.85, ceiling $3,095.12) in the October 2026 file. Its 2026 Q4 MUEs per date of service: DME supplier 1 (MAI 2, Code Descriptor / CPT Instruction). A4594 appears in no active LCD or billing and coding article, so coverage follows HCPCS coverage code C (carrier judgment, so the Medicare contractor decides coverage) and any NCD. OPPS status indicator E1: Non-allowed item or service. HCPCS record: BETOS D1E (other DME); pricing indicator 32; type of service P (lump-sum purchase of DME, prosthetics or orthotics). 1 other active code opens with "Neuromodulation stimulator system"; related codes: A4593, A4595, A4604, A4575.

A4594 descriptor and code status

The October 2026 HCPCS Level II file describes A4594 as “Neuromodulation stimulator system, adjunct to rehabilitation therapy regime, mouthpiece each”. It sits in the A section (transportation, medical and surgical supplies, administrative, miscellaneous and investigational), listed with the other A codes.

HCPCS file attributes of A4594
FieldValue
Short descriptorNeuromod adj rehab mouthpie
Added to HCPCS2024-04-01
Last actionN (no maintenance), effective 2025-01-01
Coverage codeC: carrier judgment, so the Medicare contractor decides coverage
Pricing indicator32: DMEPOS inexpensive and routinely purchased DME (floors and ceilings)
BETOS categoryD1E: other DME
Type of serviceP: lump-sum purchase of DME, prosthetics or orthotics

Medicare payment for A4594

DMEPOS fees for A4594, a IN (inexpensive and other routinely purchased items) item, run NU (purchased, new) $3,095.12 in every contiguous state (floor $2,630.85, ceiling $3,095.12) in the October 2026 file. The amounts below are national figures from the October 2026 CMS files; the contractor applies the locality, rural or state adjustment and the beneficiary's cost sharing.

Physician fee schedule (RVU26D)

Status X: statutory exclusion: not a physician service under the fee schedule. Global period XXX (global surgery concept does not apply); PC/TC indicator 9 (professional/technical concept does not apply).

DMEPOS fee schedule (DME26-D)

Jurisdiction D (DME MAC), payment category IN (inexpensive and other routinely purchased items). Fees are set per state; AK, HI, PR and VI are not subject to the national ceiling and floor and are listed separately. A rural fee applies only in ZIP codes on the CMS rural ZIP list.

DMEPOS fees for A4594 by modifier
ModifierFloor / ceilingNon-rural state rangeRural rangeAK / HI / PR / VI
NU (purchased, new)$2,630.85 / $3,095.12$3,095.12 (49 states)—AK $3,095.12, HI $3,095.12, PR $3,095.12, VI $3,095.12

Hospital outpatient (OPPS Addendum B)

Status indicator E1 (Non-allowed item or service), with no separate OPPS payment rate.

Medically Unlikely Edits for A4594

Its 2026 Q4 MUEs per date of service: DME supplier 1 (MAI 2, Code Descriptor / CPT Instruction). The DME supplier MUE is a date-of-service policy edit: units above the limit deny even when split across lines, and appeals rarely succeed.

MUE values for A4594 by setting
SettingMUE (units/DOS)MAICMS rationale
DME supplier12 Date of Service Edit: PolicyCode Descriptor / CPT Instruction

The MUE lookup for A4594 shows every setting next to any other code on the same claim.

NCCI edits and add-on rules

No active practitioner PTP pair lists A4594 in v323r0.

A4594 is neither an add-on code nor a designated primary code in the 2026 Q4 NCCI add-on edit file.

Pair counts show exposure, not the answer for one claim. Check A4594 against a second code to see whether the pair bundles and whether a modifier can separate the services.

Medicare coverage policies for A4594

No current LCD or billing and coding article lists A4594. The HCPCS coverage code C means carrier judgment, so the Medicare contractor decides coverage, and any National Coverage Determination for the service still applies.

Denials to expect on A4594

CARC 50 · N115

the service is not reasonable and necessary for the diagnosis on the claim

CARC 151 · N362

units of A4594 exceed the DME supplier MUE of 1 per date of service

CARC 4

the NU payment modifier is missing or does not match the item

CARC 16

the claim lacks information needed to adjudicate the line, such as an order, NPI or required modifier

For teams evaluating QuickIntell software

Where QuickIntell fits for A4594 claims

QuickAuth coordinates the requirement checks and documentation that DME claims for A4594 depend on, with human review of each case, and QuickRCM carries claim readiness and the CARC 50, 151 and modifier denials these items draw.

See QuickAuth for requirement checksSee QuickRCM for denial follow-up
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Optional software evaluation, not payer support or help with an individual claim. For coverage or payment decisions, use the official sources on this page. Do not include patient information in a demo booking or inquiry.

Frequently asked questions: HCPCS A4594

What does HCPCS code A4594 describe?

"Neuromodulation stimulator system, adjunct to rehabilitation therapy regime, mouthpiece each" (short descriptor "Neuromod adj rehab mouthpie"), in the A section (transportation, medical and surgical supplies, administrative, miscellaneous and investigational). Added 2024-04-01; last action N (no maintenance) effective 2025-01-01.

Is A4594 a CPT code?

No. A4594 is a CMS HCPCS Level II code; CPT codes are the AMA's five-character set.

What does Medicare pay for A4594?

DMEPOS fees for A4594, a IN (inexpensive and other routinely purchased items) item, run NU (purchased, new) $3,095.12 in every contiguous state (floor $2,630.85, ceiling $3,095.12) in the October 2026 file.

How many units of A4594 can be billed per day?

Its 2026 Q4 MUEs per date of service: DME supplier 1 (MAI 2, Code Descriptor / CPT Instruction). For the DME supplier MUE (MAI 2), units above 1 deny for the whole day as a policy limit; denials arrive as CARC 151.

Does Medicare cover A4594?

A4594 appears in no active LCD or billing and coding article, so coverage follows HCPCS coverage code C (carrier judgment, so the Medicare contractor decides coverage) and any NCD.

Sources

Every figure on this page is taken from the CMS publications below, as released by the Centers for Medicare & Medicaid Services. Projection built 2026-10-10. Verify against the primary file before billing or contracting decisions. The reference methodology explains how each figure is computed from these files.

Disclaimer

This page is an operational reference compiled from CMS publications: the HCPCS Level II file, the physician, DMEPOS and clinical laboratory fee schedules, OPPS and ASC addenda, NCCI MUE, PTP and add-on edit tables and the Medicare Coverage Database. Amounts are Medicare national figures before locality and state adjustment; Medicaid and commercial payers set their own. CPT codes are shown as numbers only; CPT descriptors are copyright AMA. Nothing here is legal, clinical or billing advice.

Found a figure that does not match the CMS file? Report a data correction with the CMS file and the value you expected; the request reaches the editorial team through the contact form.