A4594 HCPCS code: Neuromodulation stimulator system, adjunct to rehabilitation therapy regime, mouthpiece each
A4594 is the HCPCS Level II code for neuromodulation stimulator system, adjunct to rehabilitation therapy regime, mouthpiece each. The 2026 Medicare DMEPOS fee schedule pays $3,095.12 (NU, new equipment, purchased) depending on the state. Its Medicare coverage code is C (Carrier judgment): Coverage is decided by the Medicare contractor (MAC) case by case. The NCCI unit limit is 1 per day on DME suppliers.
Code details
| Field | Value |
|---|---|
| Section | A codes — Transportation, medical/surgical supplies and miscellaneous |
| Coverage code | C — Carrier judgment |
| Pricing indicator | 32 — DMEPOS: inexpensive or routinely purchased item |
| BETOS category | D1E — Other durable medical equipment |
| Added | 2024-04-01 |
| Last action effective | 2025-01-01 |
2026 Medicare DMEPOS fee schedule for A4594
| Modifier | Meaning | Lowest state fee | Highest state fee | Ceiling | Floor |
|---|---|---|---|---|---|
| NU | new equipment, purchased | $3,095.12 | $3,095.12 | $3,095.12 | $2,630.85 |
| State | Modifier | Fee | Rural fee |
|---|---|---|---|
| AK | NU | $3,095.12 | — |
| AL | NU | $3,095.12 | — |
| AR | NU | $3,095.12 | — |
| AZ | NU | $3,095.12 | — |
| CA | NU | $3,095.12 | — |
| CO | NU | $3,095.12 | — |
| CT | NU | $3,095.12 | — |
| DC | NU | $3,095.12 | — |
| DE | NU | $3,095.12 | — |
| FL | NU | $3,095.12 | — |
| GA | NU | $3,095.12 | — |
| HI | NU | $3,095.12 | — |
| IA | NU | $3,095.12 | — |
| ID | NU | $3,095.12 | — |
| IL | NU | $3,095.12 | — |
| IN | NU | $3,095.12 | — |
| KS | NU | $3,095.12 | — |
| KY | NU | $3,095.12 | — |
| LA | NU | $3,095.12 | — |
| MA | NU | $3,095.12 | — |
| MD | NU | $3,095.12 | — |
| ME | NU | $3,095.12 | — |
| MI | NU | $3,095.12 | — |
| MN | NU | $3,095.12 | — |
| MO | NU | $3,095.12 | — |
| MS | NU | $3,095.12 | — |
| MT | NU | $3,095.12 | — |
| NC | NU | $3,095.12 | — |
| ND | NU | $3,095.12 | — |
| NE | NU | $3,095.12 | — |
| NH | NU | $3,095.12 | — |
| NJ | NU | $3,095.12 | — |
| NM | NU | $3,095.12 | — |
| NV | NU | $3,095.12 | — |
| NY | NU | $3,095.12 | — |
| OH | NU | $3,095.12 | — |
| OK | NU | $3,095.12 | — |
| OR | NU | $3,095.12 | — |
| PA | NU | $3,095.12 | — |
| PR | NU | $3,095.12 | — |
| RI | NU | $3,095.12 | — |
| SC | NU | $3,095.12 | — |
| SD | NU | $3,095.12 | — |
| TN | NU | $3,095.12 | — |
| TX | NU | $3,095.12 | — |
| UT | NU | $3,095.12 | — |
| VA | NU | $3,095.12 | — |
| VI | NU | $3,095.12 | — |
| VT | NU | $3,095.12 | — |
| WA | NU | $3,095.12 | — |
| WI | NU | $3,095.12 | — |
| WV | NU | $3,095.12 | — |
| WY | NU | $3,095.12 | — |
How the A4594 fee compares
| Measure | Value |
|---|---|
| Rank among 1 A45 codes billed NU (lowest = 1) | 1 |
| Family fee range (average of state fees) | $3,095.12–$3,095.12 |
| Rural fee uplift | — |
NCCI unit limits (MUE)
| Claim type | Max units per day | Rationale |
|---|---|---|
| DME suppliers | 1 | Code Descriptor / CPT Instruction |
What changed for A4594
- 2026-01-01: Average state fee (NU) rose 2.0%: $3,034.43 to $3,095.12
- 2024-04-01: A4594 added to HCPCS Level II
- Next scheduled CMS quarterly update (HCPCS and DMEPOS fee schedule): 2027-01-01
Frequently asked questions
What is HCPCS code A4594?
A4594 is the HCPCS Level II code for neuromodulation stimulator system, adjunct to rehabilitation therapy regime, mouthpiece each. Short descriptor: "Neuromod adj rehab mouthpie".
How much does Medicare pay for A4594?
Under the 2026 DMEPOS fee schedule, non-rural state fees are NU (new equipment, purchased): $3,095.12. Rural fees can be higher.
Does Medicare cover A4594?
Coverage code C — Carrier judgment. Coverage is decided by the Medicare contractor (MAC) case by case.
Did the Medicare fee for A4594 change in 2026?
The average non-rural state fee for NU moved from $3,034.43 in 2025 to $3,095.12 in 2026 (+2.0%). CMS's next quarterly HCPCS and DMEPOS update takes effect January 1, 2027.
How many units of A4594 can be billed per day?
1 on DME suppliers (NCCI medically unlikely edits).
Related A45 codes
- A4500 — Surgical stockings below knee length, each
- A4510 — Surgical stockings full length, each
- A4520 — Incontinence garment, any type, (e.g., brief, diaper), each
- A4540 — Distal transcutaneous electrical nerve stimulator, stimulates peripheral nerves of the upper arm
- A4541 — Monthly supplies for use of device coded at e0733 ($40.40–$49.25)
- A4542 — Supplies and accessories for external upper limb tremor stimulator of the peripheral nerves of the wrist ($526.85–$526.85)
- A4543 — Supplies for transcutaneous electrical nerve stimulator, for nerves in the auricular region, per month
- A4544 — Electrode for external lower extremity nerve stimulator for restless legs syndrome ($6.34–$6.34)
- A4545 — Supplies and accessories for external tibial nerve stimulator (e.g., socks, gel pads, electrodes, etc.), needed for one month ($38.21–$55.51)
- A4550 — Surgical trays
- A4553 — Non-disposable underpads, all sizes
- A4554 — Disposable underpads, all sizes
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Next steps
- Run a reimbursement report for a device billed under A4594
- Watch A4594 for fee, coverage and descriptor changes
- Build a full Medicare revenue model for A4594
Sources: CMS HCPCS Level II release October 2026; CMS DMEPOS fee schedule 2026; CMS NCCI MUE tables; CMS Medicare utilization (physician and DME supplier files); CMS Medicare Coverage Database articles. Fees are Medicare allowables, not commercial rates. Not billing or legal advice.