HCPCS Q4331: Wound matrixMedicare rate & RVUs in Guam
Report Q4331 for each square centimeter of Axolotl graft furnished for wound treatment, alongside the primary procedure for its application.
Medicare pays $144.69 for Q4331 in the office in Guam (Hawaii, Guam). Which amount applies depends on the service address.
Medicare allowed amount for participating (non-QP) physicians, before deductible, coinsurance and claim adjustments. Not a patient’s bill or a hospital charge.
On this page 9 sections
What Q4331 covers
Q4331 identifies Axolotl graft, a biologic wound matrix used as a material in wound care. Clinicians may apply it to a prepared wound bed during treatment of a chronic or otherwise difficult-to-heal wound, including in an outpatient wound clinic or a surgical setting. The code represents the specific Axolotl product, not the clinician’s wound assessment or the application service itself.
Report the documented square-centimeter quantity with the primary procedure for applying the graft; CMS treats Q4331 as an add-on, paid within that procedure’s global period. Keep records showing the product used, wound treated, and quantity applied. CMS assigns no physician work RVUs to this product code and classifies it as technical-component-only, with interpretation covered by a separate code. The CMS classification should be followed when determining how the service is represented on the claim.
This summary was written with AI assistance from CMS physician fee schedule data and checked against the CMS billing rules shown here. Rates on this page come directly from CMS files.
Q4331 in Hawaii, Guam
| Payment locality | Office | Facility |
|---|---|---|
| Hawaii, Guam | $144.69 | Unavailable |
How the Q4331 rate is calculated
Each of Q4331’s three RVUs is multiplied by a geographic index (GPCI) for the payment locality, added up, and multiplied by the conversion factor. Drag the indexes or enter a ZIP to see what moves the rate.
How the rate is built · Q4331
RVUs × geographic indexes × conversion factor
Swap in your local Medicare rate.
Work 0.00Practice expense 3.81Malpractice 0.00
All indexes start at 1.000 (the national rate). Enter a ZIP or drag a slider.
Payment rules and modifiers for Q4331
The CMS indicators that decide how Q4331 is paid alongside other services.
CMS payment indicators · Q4331
Wound matrix
| Rule | CMS value | What it means |
|---|---|---|
| Global period | ZZZ | Add-on code: falls within the primary procedure’s global period. |
| Multiple procedures | 0 | No multiple-procedure reduction. |
| Bilateral (modifier 50) | 0 | The 150% bilateral adjustment doesn’t apply. |
| Assistant at surgery (80/81/82/AS) | 0 | Not paid without supporting documentation. |
| Co-surgeons (62) | 0 | Not permitted. |
| Team surgery (66) | 0 | Not permitted. |
| Professional/technical | 3 | Technical component only. |
Q4331 compared with similar codes
Compare codes
Q4331 vs Q4332 vs Q4323 vs Q4324: national Medicare rates
Swap in your local Medicare rate.
How to choose
- Q4332Wound graft
- Q4331 identifies Axolotl graft, while Q4332 identifies Axolotl dualgraft. Use the code for the specific product applied.
- Q4323AlloPly
- Q4323 identifies Alloply rather than Axolotl. These product codes are not interchangeable based on wound area.
- Q4324Amniotic graft
- Q4324 identifies Amniotx rather than Axolotl. Select according to the product documented as used.
Q4331 billing questions
How is Q4331 distinguished from Q4332?
Q4331 identifies Axolotl graft; Q4332 identifies Axolotl dualgraft. Select the code matching the product used, rather than choosing by wound size or location.
Can Q4331 be billed by itself?
No. CMS identifies it as an add-on code that must be billed with a primary procedure, and payment falls within that procedure’s global period.
What quantity should be reported?
Report the documented square-centimeter quantity of Axolotl graft. The record should support the amount applied to the wound.
Does Q4331 represent the graft application service?
No. Q4331 identifies the Axolotl product; report it with the primary procedure that represents application of the graft.
What documentation supports Q4331?
Document the Axolotl product, the wound treated, and the square-centimeter quantity applied, along with the primary procedure.
Where these rates come from
FeeBase calculates base physician payments from CMS work, practice-expense and malpractice RVUs, adjusted by each locality’s geographic indexes and the conversion factor. Services without a published rate are labeled, never given a made-up amount. Amounts are Medicare allowed amounts before claim adjustments: not a patient’s bill or a commercial rate.
CMS RVU26D · effective Oct 1, 2026 through the day before Jan 1, 2027
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