HCPCS Q4138: Wound matrixMedicare rate & RVUs in Oregon
Reports one-square-centimeter units of BioDflex DryFlex, a dehydrated amniotic tissue product applied to a prepared wound bed during wound care.
Medicare pays $126.75–$141.38 for Q4138 in the office in Oregon, from Rest Of Oregon to Portland. 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 Q4138 covers
BioDflex DryFlex is a dehydrated amniotic tissue allograft supplied for placement over a prepared wound. Wound care clinicians, podiatrists, and surgeons may use it in outpatient wound clinics, physician offices, or hospital settings when treating wounds such as diabetic foot or venous leg ulcers. The product is placed on the wound bed as part of the treatment; the code represents the product, not the clinical work of preparing and treating the wound.
Report units on the code’s one-square-centimeter basis, and document the product used, wound site and dimensions, and the amount applied. CMS classifies Q4138 as an add-on code: report it only with a primary procedure, and its payment falls within that procedure’s global period. CMS also classifies it as technical-component-only, with a separate code covering interpretation.
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 Q4138 pays more and less in Oregon
| Payment locality | Office | Facility |
|---|---|---|
| Portland | $141.38 | Unavailable |
| Rest Of Oregon | $126.75 | Unavailable |
How the Q4138 rate is calculated
Each of Q4138’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 · Q4138
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 Q4138
The CMS indicators that decide how Q4138 is paid alongside other services.
CMS payment indicators · Q4138
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. |
Q4138 compared with similar codes
Compare codes
Q4138 vs Q4140 vs Q4137 vs Q4139: national Medicare rates
Swap in your local Medicare rate.
How to choose
- Q4140BioD-Fence
- Use Q4138 for BioDflex DryFlex and Q4140 for BioDfence. The product name, not the shared area-based unit, distinguishes these codes.
- Q4137Wound matrix
- Q4137 identifies AmnioExcel or BioDExcel; Q4138 identifies BioDflex DryFlex. Both are area-based product codes, but they represent different products.
- Q4139Amnio or biodmatrix, inj 1cc
- Q4139 is for an injectable amniotic or BioDmatrix product measured by volume. Q4138 is for the dry BioDflex product measured by area.
Q4138 billing questions
How is Q4138 distinguished from Q4140?
Q4138 identifies BioDflex DryFlex, while Q4140 identifies BioDfence. Both descriptors use a one-centimeter unit, but the product name determines the code.
What unit should be reported?
The code is measured per square centimeter. Document the wound dimensions and the quantity of BioDflex DryFlex used to support the reported units.
Can Q4138 be billed by itself?
No. CMS designates it as an add-on code, so it must be reported with a primary procedure.
Is interpretation included in Q4138?
CMS identifies Q4138 as technical-component-only; a separate code covers interpretation.
How does Q4138 differ from Q4139?
Q4138 is for BioDflex DryFlex measured by area. Q4139 identifies an injectable amniotic or BioDmatrix product measured by volume.
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
Show the CMS file lines behind this rate
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