HCPCS code Q4149 – Excellagen, 0.1 cc

Key takeaways

HCPCS code Q4149 covers Excellagen, a professional-use topical wound gel made from fibrillar type I bovine collagen.

The code is billed in 0.1 cc increments of gel dispensed, not per square centimeter of wound area. One 0.5 cc syringe equals 5 units.

Excellagen is a flowable dressing rather than a sheet graft, so the graft application codes 15271 to 15278 do not apply.

Coverage is restricted. UnitedHealthcare’s commercial policy lists Excellagen as unproven and not medically necessary, so verify benefits before you open a syringe.

Practice management software like Pabau connects the volume recorded in the note to the units submitted on the claim.

Clinical application: What product does HCPCS code Q4149 cover?

Q4149 covers Excellagen, a syringe-based topical gel formulated from fibrillar type I bovine collagen at a 2.6% concentration. It is supplied as sterile, single-use pre-filled syringes with flexible applicators, and a clinician applies it directly to the wound bed immediately after debridement.

Excellagen is not human tissue and it is not a graft. The collagen is bovine in origin, and the gel flows into the wound rather than sitting on it as a membrane. That makes it workable on irregular wound shapes and on tunneled or undermined wounds, where sheet products do not conform well.

The product reached the market through Cardium Therapeutics after FDA 510(k) clearance in 2011. It later moved to Olaregen Therapeutix, a Generex Biotechnology subsidiary, which is the manufacturer named in current payer policies. The HCPCS descriptor has not changed through those transfers.

Excellagen carries unusually broad FDA labeling for a wound care product. The clearance covers acute and chronic wounds across several categories, which is why the code turns up in podiatry, vascular, and dermatologic settings alike.

Labeled applications include:

• Diabetic foot ulcers and other chronic vascular ulcers
• Venous leg ulcers and pressure ulcers
• Partial and full-thickness wounds, including tunneled and undermined wounds
• Surgical wounds such as donor sites, post-Mohs sites, podiatric wounds, and dehiscence
• Trauma wounds, including abrasions, lacerations, skin tears, and second-degree burns
• Draining wounds where a flowable dressing suits the wound contour

A product can carry broad FDA labeling and still sit outside every payer’s coverage policy. Each Medicare Administrative Contractor (MAC) sets its own Local Coverage Determination (LCD) for advanced wound care products. Those policies list the specific HCPCS codes they will pay.

A practice billing Q4149 in Noridian’s jurisdiction may face different criteria than one in Palmetto GBA’s jurisdiction. Search your own MAC’s LCD database before you treat, and read the billing and coding article attached to the policy.

How to bill Q4149: Units, modifiers, and place of service

Billing Q4149 correctly requires three inputs from the date of service. You need the volume of gel dispensed, expressed in 0.1 cc units. You also need the right modifier for the anatomical site or service context, plus the applicable place of service code. Getting any one of these wrong is enough for a claim to reject or deny.

There is a fourth rule that catches practices new to this code. Excellagen is a flowable dressing rather than a graft. CMS billing guidance says skin substitute graft codes are not to be reported for non-graft wound dressings. The guidance names gels, powders, ointments, foams, and liquids. Reporting CPT 15271 to 15278 with Q4149 is treated as incorrect coding.

Calculating Q4149 units in 0.1 cc increments

Units for Q4149 equal the volume of Excellagen dispensed, counted in 0.1 cc increments. Wound length and width do not enter the calculation at all. The process has four steps:

1. Record the volume dispensed: Note which syringe size was opened, and how much gel went into the wound in cubic centimeters.
2. Convert to 0.1 cc units: Divide the volume by 0.1. A 0.5 cc syringe equals 5 units, and a 1.0 cc dose equals 10 units.
3. Bill only what was dispensed: The unused portion of a single-use syringe is not automatically payable, and payer rules on discarded product vary. Confirm your payer’s wastage policy before you bill any remainder.
4. Document contemporaneously: The note on the date of service must carry the product name, lot number, expiration date, and the volume applied. Retrospective additions do not survive an audit.

Wound size still matters clinically, even though it does not set the unit count. Manufacturer guidance pairs one 0.5 cc syringe with wounds of up to roughly 5.0 sq cm. A large dose on a small wound invites a medical necessity review. Record wound length, width, and depth alongside the volume dispensed.

The common error on this code runs in the opposite direction from sheet products. The arithmetic below shows how far apart the two methods land. A coder who treats Q4149 like its neighbors bills the wound area, so a 6 sq cm wound goes out as 6 units. If a single 0.5 cc syringe treated that wound, the correct figure is 5 units.

Common modifiers used with Q4149

Modifiers give payers the anatomical and service-context information that affects adjudication. The table below lists the modifiers most commonly appended to Q4149 claims:

Modifier requirements vary by MAC. Some contractors require KX to confirm that policy criteria are met, while others will simply request the documentation on audit. Because coverage for Excellagen is uncertain with most payers, the GA modifier and a signed ABN matter more here than on a covered graft code.

Place of service codes used with Q4149 most frequently include POS 11 (office), POS 22 (on-campus outpatient hospital), and POS 19 (off-campus outpatient hospital). The payment rate can differ between facility and non-facility settings, so verify the applicable fee schedule using the correct POS designation.

Medicare coverage and reimbursement for Q4149

Medicare payment for Q4149 is harder to pin down than for the sheet grafts around it, and the reason is the gel format. National and local policy for skin substitutes is built around graft application, and a flowable dressing does not fit that frame.

MAC billing guidance is explicit on the point. Skin substitute graft codes are not to be reported for the application of non-graft wound dressings such as gels, powders, ointments, foams, and liquids. Under that rule, the gel is a supply furnished with the wound care visit. The payable procedure is the debridement or wound care service you actually performed.

CMS then reset the whole category for CY 2026. Skin substitute products are now paid as incident-to supplies when used with a covered application procedure. The rate is a single national figure of roughly $127 per square centimeter, replacing product-specific average sales price.

That rate is expressed per square centimeter, which is not Q4149’s unit. A code measured in 0.1 cc increments does not map onto an area-based payment amount. Ask your MAC how it prices this code before you quote a patient any figure.

Payment status also moves with each CMS quarterly update. Verify the current status for Q4149 through the CMS Physician Fee Schedule search tool before you calculate expected reimbursement.

Why the skin substitute LCDs may not cover Q4149

Local Coverage Determinations (LCDs) list the products a MAC will pay for, code by code. That list sits in a policy table attached to the LCD or its billing and coding article. The bioengineered skin substitute LCDs are written around graft products applied to lower extremity chronic wounds, and Q4149 does not appear on those covered-code tables. Check these five things in your own jurisdiction:

• Whether Q4149 appears in the LCD’s covered HCPCS table at all, searched by code rather than by product category
• Minimum duration of standard wound care before any advanced product is covered (commonly four weeks for diabetic foot ulcers)
• Required wound measurements, photography, and treatment history documentation
• Frequency limits per wound episode, and whether the product is bundled into the wound care visit
• Conditions that make a patient ineligible, such as active infection or untreated inadequate perfusion

The major MACs with skin substitute policies include Noridian, Palmetto GBA, CGS Administrators, Novitas Solutions, WPS Government Health Administrators, and First Coast Service Options. Search by the code Q4149 rather than the phrase “skin substitute,” because the phrase returns graft policies that do not govern this product.

Commercial policy is more direct. UnitedHealthcare’s commercial medical policy for skin and soft tissue substitutes lists Excellagen as unproven and not medically necessary for any indication. The policy cites insufficient published evidence. Other national payers take comparable positions, so insurance eligibility verification belongs before the appointment, not after the denial.

Where coverage is unlikely, handle it before treatment rather than after the denial. Issue an advance beneficiary notice, have the patient sign it, and append the GA modifier to the claim. Practices that skip that step write off the product cost. A denied non-covered supply cannot be billed to the patient without the signed notice.

ICD-10 diagnosis codes commonly paired with Q4149

Every Q4149 claim needs a supporting ICD-10-CM diagnosis code that establishes the clinical reason for the wound care episode. The code must reflect the wound type, anatomical site, and laterality documented in the note. Vague or unspecified wound codes are common denial triggers, because they do not show the chronic, treatment-resistant character that payer policies look for.

The table below lists the ICD-10-CM codes most often paired with Q4149 claims, drawn from the wound types in Excellagen’s labeling. Treat it as a reference. Confirm that the code you pick is supported by the clinical note and appears on your payer’s covered diagnosis list.

Use the highest-specificity code available. An unspecified code, such as L97.419 where the note documents the ulcer stage, signals thin documentation and may fail the payer’s diagnosis specificity test.

Check your full code combinations against the covered diagnosis list published with your MAC’s policy. The ICD-10-CM code library carries the wound and ulcer entries in full. That includes the staged pressure ulcer codes payers expect on a chronic wound claim.

Documentation requirements for medical necessity

Thin documentation drives Q4149 denials and post-payment audits. The note on the date of service has to support every element of the claim. That means the wound’s identity, its chronic nature, and its failure to respond to prior treatment. It also means the reason a collagen gel was chosen, plus the volume dispensed. A line reading “applied collagen gel to right foot wound” supports none of that.

Strong documentation for a Q4149 claim includes all of the following elements:

• Wound identification: anatomical site, laterality, wound type (diabetic ulcer, venous ulcer, pressure injury), and duration of the wound in weeks or months
• Current wound measurements: length, width, and depth in centimeters, recorded on the date of service; they support medical necessity, not the unit count
• Standard care history: documentation covering the payer’s required observation period, commonly four weeks, showing standard care was given and the wound did not heal
• Prior treatments documented: offloading for DFUs, compression therapy for VLUs, debridement records, antimicrobial dressings used, and patient adherence notes
• Product identification: product name (Excellagen), manufacturer, lot number, expiration date, and the syringe size opened
• Application note: the debridement performed first, how the gel was spread across the wound bed, the volume dispensed, and the dressing applied over it
• Units reconciliation: the volume in the note converted to 0.1 cc units, matching the unit count submitted on the claim line
• Medical necessity statement: a brief clinician attestation explaining why a collagen gel was chosen at this time, with reference to prior treatment failure

Keep wound measurement flowsheets and a standard care log in the patient’s ongoing record. Flowsheets are the fastest way to show the required treatment history during an audit. Consistent documentation standards across the wound care team also reduce the record-to-record variation that triggers denials.

Q4149 vs. neighboring Q4100-series HCPCS codes

Q4149 sits within the Q4100-series alongside hundreds of other product codes. Each one is assigned to a specific product or product line, and they are not interchangeable. Billing Q4148 when the product dispensed was Excellagen is a coding error that creates audit liability, even where the clinical goal was the same.

The table below puts Q4149 next to the three codes around it. Three of the four are per-square-centimeter human tissue products, while Q4149 is the dosage-based bovine collagen gel. Verify the current descriptor for each code with the AAPC HCPCS code lookup alongside the CMS release file.

The unit column is the one to memorize. Q4148, Q4150, and Q4151 are add-on codes reported with a graft application procedure. Q4149 is neither area-based nor a graft, so it follows different rules end to end.

The correct code is set by the product dispensed, not by the clinical indication. Confirm the assignment with the manufacturer’s billing department or the product’s HCPCS assignment letter from CMS. Where your MAC requires PDAC (Pricing, Data Analysis, and Coding) verification, that letter names the code to use.

Common billing errors and denial reasons for Q4149

Wound care product billing has one of the highest denial rates in the outpatient setting. The OIG has flagged Q-series codes in multiple reports, and some MACs run targeted pre-payment review on high-volume Q-code billers. Knowing the specific denial patterns for Q4149 is the fastest way to cut your rework burden.

The most frequent denial reasons, and how to address each one:

• Units billed as square centimeters: The claim carries the wound area instead of the volume of gel dispensed. Fix: build the 0.1 cc conversion into charge capture, so the cc figure in the note becomes the unit count automatically.
• Reported with a graft application code: Q4149 submitted alongside CPT 15271 to 15278. Fix: report the debridement or wound care service actually performed, and reserve the graft application codes for sheet products.
• Coverage never verified: The product was applied before anyone checked whether the payer considers it payable. Fix: run the benefits check at scheduling, and obtain a signed ABN with the GA modifier where coverage is unlikely.
• Missing standard care history: The record lacks documentation of prior wound care attempts over the required observation period. Fix: maintain a four-week wound care flowsheet and attach it to the record before billing any advanced product.
• Wrong HCPCS code for the product applied: The code billed does not match the product’s CMS-assigned HCPCS code. Fix: confirm the code with the manufacturer before purchasing and set up product-to-code mappings in your billing system.
• Diagnosis code too unspecified: A generic wound code was used instead of the highest-specificity ICD-10-CM code for the wound type, site, and stage. Fix: train clinicians on wound care specificity and audit a sample of records monthly.
• Prior authorization not obtained: The service was submitted without the payer’s required authorization. Fix: run a prior-authorization check as part of the pre-service workflow for every wound product appointment.
• KX modifier absent when required: The payer requires KX to signal policy compliance, but the claim went out without it. Fix: add KX to your Q4149 claim template where the policy requires it, and audit claims monthly for modifier compliance.

When a Q4149 claim is denied, pull the remittance advice and read the Claim Adjustment Reason Code (CARC). Each CARC maps to a denial type, which tells you whether the problem was the unit count, the documentation, or the coverage decision.

How practice management software prevents Q4149 unit and coverage errors

Manual HCPCS workflows for wound care products create several points of failure. Units get converted on paper, and modifiers are added from memory. Coverage is checked after the syringe has already been opened, and diagnosis codes are picked without a look at the payer’s covered list.

Pabau’s tools for cleaner claims management connect clinical documentation to claim preparation in one platform. Clinicians record the product name, lot number, and volume dispensed in structured fields on the date of service. Those values carry into the claim instead of being retyped from a paper note.

Claims go to US payers electronically, with eligibility and prior-authorization status checks running before each appointment. For a code with coverage as uncertain as Q4149, catching the benefits problem at scheduling is worth more than any appeal filed later.

High-volume wound care practices feel this most. The volume in the note becomes the unit count on the claim without a manual step. Fewer claims age into denials, and fewer staff hours go to rework.

Keep Q4149 units and coverage checks in one place

Pabau’s claims management tools capture the volume dispensed in structured fields, run eligibility checks before the appointment, and submit to US payers electronically. See how it works for a wound care practice.

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Conclusion

Q4149 claims fail for two reasons, and neither is clinical. The first is a unit error, where the claim carries wound area in square centimeters instead of the volume of gel dispensed. The second is a coverage problem, because many payers treat Excellagen as unproven and were never going to pay.

Both are fixable before the patient is treated. Verify benefits at scheduling, document the volume in the procedure note, and convert that volume to units at charge capture rather than from memory.

The trade-off worth remembering is small: a signed advance beneficiary notice costs two minutes, while a denied syringe costs the product. Book a demo to see how Pabau keeps the volume you documented and the units you billed in step.

Continue your research

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