Collagen dressings and Medicare: codes, coverage and the PDAC listing

The six collagen codes

LCD L33831 groups six HCPCS codes under collagen: two fillers billed per gram of collagen, three dressings billed each by size, and one filler billed per 6 inches. The descriptors below are CMS's wording.

Size bands work as they do for other dressings. A 4×4 sheet is 16 sq. in., inside the first band; a 7×7 is 49 sq. in., above 48. All six codes are on the Policy Article's list of codes that need an A1–A9 modifier for the number of qualifying wounds the code is used on. For CMS's wording of any other dressing code, use the HCPCS code lookup.

When Medicare covers collagen

Collagen starts where every surgical dressing does: with a qualifying wound, meaning a wound caused by, or treated by, a surgical procedure, or a wound after debridement (Policy Article A54563). The LCD then covers a collagen-based dressing or wound filler for:

• full thickness wounds (e.g., stage 3 or 4 ulcers);
• wounds with light to moderate exudate; or
• wounds that have stalled or have not progressed toward a healing goal.

It also sets exclusions: “Collagen based dressings are not covered for wounds with heavy exudate, third-degree burns, or when an active vasculitis is present.” Choosing collagen for a given wound is a clinical decision. The policy sets the conditions, and the record has to show they're met.

A wear time, not a change frequency

For most dressing types, the LCD states a usual maximum change frequency: up to once per day for alginate, up to 3 times per week for foam wound covers, and so on. For collagen it says something different: “They can stay in place up to 7 days.”

That sentence describes how long a collagen dressing can stay on. It isn't a usual maximum change frequency, and the LCD doesn't state one for collagen. Two general rules in the LCD still apply when collagen is used with a cover dressing:

• “For purposes of this policy, the product in contact with the wound determines the change frequency.”
• “It is not reasonable and necessary to use a combination of products with differing change intervals.”

As with any dressing, the initial evaluation must record the frequency of dressing change, and the order's quantities should follow it. To turn a documented frequency into a monthly estimate, use the quantity calculator.

The PDAC listing rule for A6021–A6024

This rule decides whether a product can be billed with a collagen dressing code at all. Under the Policy Article, for dates of service on or after June 1, 2013, the only products that may be billed with A6021, A6022, A6023 or A6024 are those with a written coding verification review (CVR) by the Pricing, Data Analysis, and Coding (PDAC) contractor, published on the Product Classification List (PCL).

If a product is billed with one of those codes but isn't on the PCL for that code, “the claim line will be denied as incorrect coding.” The requirement names A6021–A6024. The Policy Article doesn't apply it to the per-gram collagen filler codes A6010 and A6011.

PDAC's earlier collagen advisories, from 2012 and 2013, are now listed as retired. The Policy Article is the current text.

How to check the listing

1. Open DMECS, the PDAC's Durable Medical Equipment Coding System. It's the “Search DMECS for Codes and Fees” link on the PDAC website.
2. Search the Product Classification List. PDAC's DMECS Basics page says you can search it by manufacturer or distributor name, HCPCS code, product name, product model or classification.
3. Confirm the exact product, by name and model, is listed under the code you plan to bill.
4. Check again before you rely on an old lookup. PDAC's list of items requiring coding verification, which includes A6021–A6024, says “Coding decisions are updated frequently” and advises users to “check the Product Classification List often.”

Only products that have been submitted for coding verification appear on the PCL. If a product isn't listed, PDAC's guidance is to contact PDAC for coding assistance.

Silver collagen

Each PCSS collagen sheet size also comes in a silver version. The LCD lists silver among materials whose safety and effectiveness “have not been established,” but it doesn't say every dressing containing silver is non-covered. Instead:

• “Dressings containing multiple components are classified based upon the clinically predominant component.”
• When a single material makes up more than 50% of a product by weight, the product is “coded based upon the applicable specific HCPCS code for that material” (Policy Article).
• Multi-component dressings made predominantly of materials not recognized as effective “are not considered reasonable and necessary.”

In practice, a silver collagen dressing billed with A6021–A6024 needs its own PDAC listing under the code billed. Check it the same way as any other collagen product.

PCSS collagen products

A 2×2 sheet is 4 sq. in. and a 4×4 is 16 sq. in., both within A6021's “16 sq. in. or less”; a 7×7 is 49 sq. in., within A6023's “more than 48 sq. in.” PCSS suggests these codes for reference only. A6021 and A6023 can be billed only if the exact product is on the PDAC Product Classification List under that code — ask us for the listing and check DMECS before you dispense. Confirm final coding with your billing staff.

Collagen also anchors all three PCSS wound care kits: CMS10 uses 2×2 sheets, CMS11 uses 4×4 sheets and CPS10 uses collagen particles. See our wound care kits guide, and our patient-direct guide for sending collagen home.

Questions

Sources

Checked on October 6, 2026. Medicare policy changes; confirm current versions before relying on them. This page is general information, not billing, coding or legal advice.