HCPCS code Q4131: Epifix or Epicord, now Q4186/Q4187

Key Takeaways

HCPCS code Q4131 covered Epifix or Epicord, MiMedx skin substitute grafts billed per square centimeter of wound coverage

CMS deleted Q4131 on January 1, 2019, not 2025, splitting it into Q4186 for Epifix and Q4187 for Epicord

Since January 1, 2026, Medicare pays non-biological skin substitutes like Epifix and Epicord at one flat rate near $127 per square centimeter, as an incident-to supply, instead of the old high-cost/low-cost split

Practice management software like Pabau keeps product usage, invoicing, and documentation organized, so wound care claims are less likely to bounce back

Type “HCPCS code Q4131” into a search bar today, and you’ll be looking up a code that stopped working years ago. Q4131 used to cover Epifix or Epicord, two MiMedx skin grafts, billed per square centimeter of wound coverage. Medicare retired it on January 1, 2019, splitting it into two separate codes: Q4186 for Epifix and Q4187 for Epicord.

That matters if an old superbill, a saved claim template, or a coder new to wound care still has Q4131 sitting on it. Submit a claim with a dead code and the payer won’t flag it for review, they’ll deny it outright, often after the graft is already on the patient.

Here’s the code CMS actually wants instead, and how the billing around it has changed since.

HCPCS code Q4131 covered Epifix or Epicord, by the square centimeter

HCPCS code Q4131 sat in the Q-code series of HCPCS Level II, the coding system the Centers for Medicare and Medicaid Services (CMS) uses for products and supplies that CPT codes don’t cover. Its full descriptor read “Epifix or Epicord, per square centimeter.”

The code covered two related MiMedx skin substitute products: Epifix, a dehydrated human amnion/chorion membrane (dHACM) allograft made from placental tissue, and Epicord, a dehydrated human umbilical cord allograft. Both are used on chronic wounds that haven’t responded to standard care, most often diabetic foot ulcers and venous leg ulcers.

CMS retired Q4131 in 2019, six years before its rumored 2025 death

CMS didn’t touch Q4131 in 2025. It deleted the code effective January 1, 2019, at MiMedx’s own request. The manufacturer had asked CMS to split its shared code into two product-specific ones, arguing that payers needed to know which graft, Epifix or Epicord, a claim actually described. CMS agreed, retired Q4131, and created Q4186 (Epifix) and Q4187 (Epicord) in its place.

If you’ve seen a claim that Q4131 disappeared in an “April 2025 HCPCS Q-code restructuring,” that’s a mix-up with a different, later update. CMS did revise the skin substitute Q-code family that April, adding 14 new low-cost codes (Q4354–Q4367), deleting Q4231 (Corplex P), and reclassifying Q4271 (Complete FT). None of that touched Q4131, Q4186, or Q4187. By April 2025, Q4131 had already been out of use for more than six years.

Bill Q4186 for Epifix and Q4187 for Epicord, based on the product applied

The crosswalk is straightforward once you know it. If the chart says Epifix, the claim needs Q4186. If it says Epicord, use Q4187. There’s no shared code anymore, so a coder can’t default to whichever one comes up first in the practice’s system. The product name in the treatment note decides the code.

One exception: if you’re filing or correcting a claim for a date of service before January 1, 2019, bill Q4131 as it was written then. Code selection always follows the date of service, not the date you happen to be submitting the claim.

Medicare changed how it pays for these grafts again, starting January 2026

For years, Medicare split skin substitutes into “high-cost” and “low-cost” groups based on average sales price, paying high-cost products like Epifix and Epicord separately under the Outpatient Prospective Payment System (OPPS) and folding low-cost ones into the procedure payment. That split is now history.

The CY2026 Medicare Physician Fee Schedule final rule (CMS-1832-F), effective January 1, 2026, replaced it with one flat national rate, about $127 per square centimeter, for non-biological skin substitutes used during a covered application procedure.

CMS now treats these products as incident-to supplies rather than separately priced drugs. Epifix and Epicord, both 361 HCT/P allografts rather than licensed biologics, fall under this flat rate. Only products with a full Section 351 Biologics License Application still get paid at ASP+6%.

Practically, the old high-cost/low-cost label doesn’t decide payment anymore. What decides payment now is whether the graft was applied during a covered procedure, and whether you billed the right supply code alongside it.

Bill the supply code and the CPT code as two lines, not one

Q4186 and Q4187 are supply codes. They don’t stand alone on a claim; they’re billed alongside a CPT application code that describes the act of grafting the material onto the wound. That’s CPT codes 15271 through 15278, split by wound location and size, a different family from active wound care management codes like CPT 97597, which cover debridement rather than graft placement.

• 15271–15274: application to the trunk, arms, or legs
• 15275–15278: application to the face, scalp, eyelids, mouth, neck, ears, orbits, genitalia, hands, feet, or multiple digits
• Each pair starts with a first-tier wound size, then adds an add-on code for additional square centimeters

Both codes belong on the same claim, for the same date of service, but as separate line items: the supply code with its own units, the CPT code with its own. They aren’t merged into a single line.

A claim that combines them, or that carries the CPT code without the matching Q-code (or the reverse), is one of the fastest ways to get bounced back for correction.

A quick walkthrough: A 12 sq cm diabetic foot ulcer

Say a patient has a diabetic foot ulcer measuring 3 cm by 4 cm, 12 square centimeters. Because the wound is on the foot, the application falls under the 15275 family rather than 15271.

The claim needs two lines: CPT 15275 for the application (first 25 sq cm or less), and Q4186 or Q4187 at 12 units, one unit per square centimeter of graft actually applied. Both share the same date of service. Neither line substitutes for the other.

Common mistakes that trip up these claims

• Billing Q4131 for any date of service on or after January 1, 2019
• Guessing the product code instead of confirming Epifix vs. Epicord from the chart
• A unit count that doesn’t match the documented wound measurement
• Submitting the CPT application code without the paired supply code, or the reverse
• Applying the graft before the payer’s required weeks of failed conservative care are documented

Keep skin substitute claims accurate

Practice management software like Pabau keeps product usage, invoicing, and documentation organized, so your team has what it needs before a claim goes out.

Book a demo

Run this checklist before you submit the claim

Missing documentation is the most common reason a skin substitute claim lands in review instead of getting paid the first time.

1. Wound length, width, and resulting square-centimeter area, measured at the visit
2. ICD-10-CM code matching the documented wound type and location
3. Proof of prior conservative wound care that didn’t work; your MAC’s LCD sets the minimum weeks
4. Product name (Epifix or Epicord), lot number, and units used
5. Application CPT code from the 15271–15278 range, billed as its own line
6. Signed consent, plus a supervising physician’s order if a non-physician applied the graft

Skip any one of these and the claim usually comes back for correction rather than getting an outright denial, but either way it costs your team time. Requirements can vary slightly by MAC, so check the LCD your practice bills under, whether that’s CGS, Palmetto GBA, Novitas, or Noridian.

Pick the ICD-10 code that matches the wound being treated

Every skin substitute claim needs a supporting ICD-10-CM diagnosis code to establish medical necessity. The diagnosis has to reflect the wound type and be covered under the applicable LCD.

Code to the highest specificity available. A code like E11.621 carries stronger medical necessity weight than a generic wound code, and it should match the wound location documented in your measurement notes. Verify the full covered diagnosis list against your MAC’s current LCD, since covered diagnoses change with policy updates.

Diabetic foot ulcers often come with broader diabetes management needs. A practice already following a diabetes care plan for the same patient can lean on that same documentation trail to support the wound claim, alongside routine screening billed under S3000.

What Epifix and Epicord actually are, and why CMS split them

Epifix is a dehydrated human amnion/chorion membrane, dHACM for short, made from donated placental tissue. Epicord comes from the umbilical cord instead.

MiMedx processes both to preserve growth factors and structural proteins that support wound healing, and both ship as a thin sheet or mesh graft applied directly to the wound bed.

They’re similar enough that CMS billed them under one shared code for years. MiMedx pushed for the split because payers couldn’t tell from Q4131 alone which product a claim described, and that made utilization tracking and pricing harder for everyone downstream.

Splitting the code didn’t change how the products are used clinically, only how they’re identified on paper.

• Typically applied weekly for up to four weeks, then reassessed
• Used on diabetic foot ulcers, venous leg ulcers, pressure ulcers, and stalled surgical wounds
• Applied by wound care physicians, podiatrists, dermatology practices, or regenerative medicine practices
• Used only after standard wound care, offloading, compression, moist dressings, has failed to close the wound

Where Q4186 and Q4187 sit among other skin substitute codes

Q4186 and Q4187 belong to a large family of skin substitute Q-codes. Using the wrong one, or a deleted one, for a product that has its own distinct code results in a mismatch denial.

This is a small sample of a much larger family, and the list gets revised regularly. Confirm any product’s current code against the CMS HCPCS quarterly release file or the manufacturer’s own billing guide before you submit.

How practice management software keeps this billing clean

Wound care billing has a lot of small moving parts: a code that gets renamed every few years, per-square-centimeter unit math, MAC-specific documentation thresholds, and a payment model that just changed again for 2026. A practice tracking all of that from memory or a spreadsheet is going to miss something eventually.

Practice management software like Pabau keeps product usage, invoicing, and documentation organized so nothing slips before a claim goes out.

Automated workflows can route consent forms, wound care documentation, and invoicing through one system, so a practice isn’t relying on memory or a spreadsheet to catch a missing step.

Conclusion

Q4131 hasn’t been billable since January 1, 2019. If your practice applies Epifix, bill Q4186. If it’s Epicord, bill Q4187. Pair either one with the matching CPT application code from 15271 through 15278, as its own line, for the same date of service, and confirm your documentation meets your MAC’s LCD before the claim goes out.

Practice management software like Pabau can help keep the surrounding details, product usage, invoicing, and documentation, organized so fewer claims bounce back for correction.

If your wound care practice wants to tighten up skin substitute billing, book a demo to see how Pabau fits your setup.

Continue your research

Need a compliance framework for your wound care documentation? Med spa compliance workflows walks through the documentation systems that reduce audit exposure across clinical specialties.

Wondering whether you can bill an E/M visit alongside these grafts? HCPCS G2211 is the visit complexity add-on code that often applies to ongoing chronic wound management encounters.

Looking for a structured approach to clinical forms? Medical forms for clinical documentation explains how standardized intake and visit forms reduce missing data in billable encounters.

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