2026 Medical Coding Changes for Dermatology: What Your Practice Needs to Know

The 2026 coding updates addressed several areas that directly affect how you document, bill, and get reimbursed. Clinical specificity is the trend and requirement for 2026. It represents a strategic pivot by payers to ensure reimbursement accurately reflects the precise complexity of care provided.

Here’s your quick guide to some of the changes that matter the most for dermatology practices:

How does the ICD-10-CM L-code expansion change dermatology documentation?

The L00–L99 chapter covering diseases of the skin and subcutaneous tissue now includes 116 new codes for 2026, with no deletions and only two revisions. The sheer number of additional codes signals that unspecified codes could be on their way out. Keep your eyes out for the 2027 ICD-10-CM changes that become effective October 1, 2026.

Payers are increasingly triggering automatic rejections for unspecified codes when specific ones exist. So, if your EHR doesn’t account for these new changes, your billing team could see an increase in denials.

Why chronic ulcer coding requires your attention

Nonpressure chronic ulcers (L98.431–L98.A399) now come with 112 new codes. For each body site, you must choose from eight distinct severity options:

• Skin breakdown limited to the skin
• Fat layer exposed
• Necrosis of muscle
• Necrosis of bone
• Muscle involvement without evidence of necrosis
• Bone involvement without evidence of necrosis
• Other specified severity
• Unspecified severity

As you document, you’ll want to choose the highest level of specificity your documentation supports. If your documentation says “chronic ulcer of the lower leg” without noting the tissue depth, your claim is at a higher risk of being downcoded by the payer.

New flank and abscess codes: what’s changed for anatomical specificity

Another 2026 update moved flank conditions out of the general back or trunk buckets and into their own specific codes.

How does the 2026 skin substitute payment change affect dermatology practices?

This change had the broadest financial impact for dermatology practices that apply skin substitutes.

In 2026, CMS overhauled how Medicare reimburses skin substitutes. The previous ASP+6% methodology was put to rest. In its place, CMS established a single national rate of approximately $127.28 per square centimeter, treating skin substitutes as incident-to supplies.

Products are now categorized by their FDA regulatory status into three groups: PMA, 510(k), and 361 HCT/P, and would include each skin substitute in the applicable category based on its FDA approval, clearance, or self-determination. If a skin substitute is licensed under section 351 of the PHS Act, the payment methodology under section 1847A would continue to apply. The rate for the three FDA regulatory categories uses the volume-weighted average ASP for skin substitute products in each group as submitted by manufacturers, when available, and the MUC when ASP is not available. This information was available in the 2026 MPFS Final Rule.

Two notable deletions to flag from 2026:

• Q4100 Skin substitute, not otherwise specified: This code was deleted as part of CMS’s effort to eliminate unspecified, generic codes for skin substitutes.
• Q4106 Dermagraft: You’ll want to confirm whether Dermagraft falls under a PMA, 510(k), or 361 HCT/P classification before submitting another claim.

For products that aren’t reimbursable under the new framework, CMS will convert those HCPCS codes to add-on codes with a ZZZ indicator. Medicare’s system handles that flag, but you do need to know which products in your practice are affected.

For more information, review the “Skin Substitute Products by FDA Regulatory Category” file from the CMS Physician Fee Schedule Final Rule at cms.gov.

What superficial radiation therapy billing changes were made?

If your practice performs superficial radiation therapy (SRT), you’ll want to pay close attention to these changes. One thing you’ll notice: you can expect a modest reduction in what you can bill per SRT encounter under the new structure.

CMCPT code 77401 was deleted, the long-standing code for radiation treatment delivery, superficial and/or orthovoltage, per day.

It has been replaced with a new set of surface radiation therapy codes:

A few notes on 77439: It reimburses approximately $16 and covers ultrasound guidance for placement of radiation therapy fields only — not tumor monitoring. If a patient elects image-guided ultrasound monitoring to follow tumor progression or regression, that’s a noncovered procedure requiring patient consent and self-pay documentation.

CPT code 77336 (radiation physics) remains valid and can still be reported alongside the new codes. E/M codes may still be appropriate if documentation supports a significantly separate and identifiable E/M service, and they may be billable when documented separately with modifier 25.

Additionally, here are some of the deletions you’ll want to be aware of:

What’s changing in infestation coding?

In 2026, there were a few straightforward changes for practices that treat common infestations. Here are the updates:

Is audio/visual supervision permanent?

The short answer is yes. During the pandemic, CMS temporarily allowed supervising physicians to be immediately available via two-way, real-time audio/visual technology — without being physically present in the office suite. For 2026, CMS finalized that flexibility as a permanent policy.

In practice, this means that if you’re a supervising physician overseeing diagnostic tests or incident-to services, you can fulfill the direct supervision requirement through a real-time audio-visual connection. You don’t have to be in the building.

If your practice has multiple locations and you supervise remotely, this is a meaningful operational change that’s here to stay.

How ModMed can help

ModMed’s EHR software takes the guesswork out of coding by suggesting E/M and CPT codes, modifiers, and diagnosis pointers for your review and approval. This helps improve accuracy and reduce denials.

Recently, we’ve taken this precision a step further with ModMed Scribe. This AI-powered clinical documentation tool turns your conversation into suggested notes, codes, and clinical actions.

Want to learn more? Stay on top of what your dermatology practice needs to know with these educational resources.

FAQs

What are the most significant ICD-10-CM code changes for dermatology in 2026?

The 2026 update introduces 116 new codes to the L00–L99 chapter. This expansion requires dermatologists to document with higher clinical specificity, particularly for conditions like nonpressure chronic ulcers and flank-specific abscesses or cellulitis.

How does the new skin substitute payment methodology work?

CMS eliminated the ASP+6% methodology. Skin substitutes are now treated as incident-to supplies with a single national rate of approximately $127.28 per square centimeter. Products are grouped by their FDA regulatory status: PMA, 510(k), and 361 HCT/P.

Which CPT codes replace 77401 for superficial radiation therapy (SRT)?

CPT code 77401 was deleted for 2026. Practices must now use the new surface radiation therapy code family: 77436, 77437, 77438, and 77439.

Are there new codes for skin infestations?

Yes. Code B88.0 was deleted and replaced by B88.01 specifically for Demodex mite infestations, and B88.09 for other acariasis. Note that these codes explicitly exclude scabies.

Can dermatologists still use audio/visual technology for direct supervision?

Yes. CMS has made the pandemic-era telehealth flexibility permanent, allowing supervising physicians to oversee diagnostic tests or incident-to services via two-way, real-time audio/visual technology without being physically present in the office.

Sources

American Medical Association. AMA releases CPT 2026 code set.

Centers for Medicare and Medicaid. NCCI 2026 Coding Policy Manual – Chapter 3. 

Centers for Medicare and Medicaid. 2026 Physician Fee Schedule Relative Value — RVU26A.

Congress.gov. H.R.7148 – Consolidated Appropriations Act, 2026.

American Medical Association. 2026 Medicare Physician Payment Schedule and Quality Payment Program Final Rule.

American Academy of Professional Coders. CPT® 2026: The Wait Is Over.

American Society for Radiation Oncology AstroNews. Major Radiation Oncology Code Changes in 2026.

Centers for Medicare and Medicaid. 2026 Medicare Add-on Code Edits.

This blog is intended for informational purposes only and does not constitute legal or medical advice. Please consult with your legal counsel and other qualified advisors to ensure compliance with applicable laws, regulations, and standards.