HCPCS Q4331: Wound matrixMedicare rate & RVUs

Medicare pays $127.26 for Q4331 nationally in the office. Local office rates run $109.31–$183.51.

Medicare allowed amount for participating (non-QP) physicians, before deductible, coinsurance and claim adjustments. Not a patient’s bill or a hospital charge.

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.

Where Q4331 pays more and less

The same RVUs, adjusted for each area’s costs. Open a locality for its calculation, history and nearby areas.

109 of 109 payment localities

Q4331 rates by state

Office rate range in each state. Select a state to see its payment localities.

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.

Payment rules and modifiers for Q4331

The CMS indicators that decide how Q4331 is paid alongside other services.

Q4331 compared with similar codes

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.

Codes related to Q4331

Related codes aren’t interchangeable: bill the code that matches the service performed.

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

Open CMS sourceHow we calculate rates