A Complete Guide on Dermatology CPT Codes

Last Updated on August 18, 2025 by admin

Dermatology practices run on precision where every code matters. Biopsies, excisions, destruction procedures, Mohs surgery, all of them are captured with Current Procedural Terminology (CPT) codes. 

The American Medical Association updates these codes yearly, and dermatology is always a busy section. According to the American Academy of Dermatology, more than 84.5 million Americans were affected by skin diseases in a single year. 

High patient volume directly translates into frequent billing encounters, which makes coding accuracy essential.

Why Dermatology CPT Codes Matter

Insurance payers want specificity. Coders provide it through CPT coding. A claim only gets paid when it’s supported by documentation and the correct CPT code. Skin-related procedures rank among the highest volume in outpatient care. Reports from CMS show that dermatology consistently ranks within the top 10 specialties for Medicare billing volume.

Biopsy Codes – The Everyday Heroes

Skin biopsies are everywhere in dermatology coding. These codes, 11102 through 11107, cover tangential, punch, and incisional biopsies. Each additional lesion gets an add-on code. For example:

• 11102 for a tangential biopsy of the first lesion.
• 11103 if there’s another lesion.

Straightforward pattern. One lesion, base code. Additional lesions, add-on. Coders memorize this structure quickly because biopsy codes appear in almost every dermatology claim.

Lesion Destruction – Premalignant and Benign

Actinic keratoses are treated daily. The CPT world has clear rules for this:

• 17000 is for the first premalignant lesion.
• 17003 adds 2–14 lesions.
• 17004 if it goes beyond 15.

Benign lesions follow 17110 and 17111. The numbers look similar, so coders often build quick reference sheets. It is common for dermatology coding teams to keep a laminated chart on the desk. Small details like this save minutes every day.

Benign vs Malignant Excision Codes

Excision codes can look intimidating at first. They split into two main groups:

• 11400–11446 for benign lesions.
• 11600–11646 for malignant lesions.

Location and size decide the exact code. For example, a 2.1–3.0 cm benign lesion on the arm becomes 11403. Same size, but malignant? Then 11603. This is where documentation quality drives code accuracy. When providers write size clearly, coders work faster and cleaner.

Mohs Micrographic Surgery – Precision in Action

Skin cancer treatment often uses Mohs surgery. Codes here include:

• 17311 for the first stage on face, neck, hands, feet.
• 17312 for each additional stage.
• 17313 and 17314 for trunk and extremities.

The sequence matters because Mohs is staged. Coders have to track which stage belongs where. Practices with dedicated dermatology coders report lower denial rates on Mohs claims.

Repair and Closure Codes

After excision, there’s usually repair. Repairs fall into simple, intermediate, and complex. The numbers range from 12031 to 13121. Intermediate repair of a 2.5 cm wound on the arm? That’s 12031. More extensive undermining or layered closure? Then it may shift into complex repair. Understanding these definitions is critical because payers review closure documentation closely.

Pathology Codes

Every biopsy needs pathology. Common codes include:

• 88304 for Level III surgical pathology.
• 88305 for Level IV (very common in dermatology).
• 88312 for special stains.
• 88341 for immunohistochemistry.

CMS utilization data highlights 88305 as one of the most frequently billed pathology codes nationwide. Dermatology contributes a significant portion to this number.

Phototherapy and Laser Treatment

Skin disease treatments now involve advanced therapies. Coders see 96900 for UV therapy, 96910 for photochemotherapy, and 96567 for photodynamic therapy. Laser treatments have their own set, such as 96920 for the first session and 96921 for subsequent ones. Coding accuracy in this category ensures practices stay compliant while supporting patient access to innovative therapies.

Evaluation and Management (E/M) Codes

E/M codes, 99202 through 99215, still form the backbone of dermatology billing services. They apply to both new and established patients. The 2021 updates simplified coding based on time or medical decision-making. Dermatologists often bill a mix of E/M with procedural codes. Modifier -25 makes that possible by showing that a separate E/M service was provided in addition to a procedure.

Modifiers Coders Cannot Forget

Modifiers bring context. A few essentials:

• -25 for a significant, separately identifiable E/M service.
• -59 when a distinct procedural service is done.
• -76 for repeat procedures.
• RT/LT for laterality.
• -51 when multiple procedures are performed.

A report from the OIG once noted that incorrect modifier use is a top reason for claim denials. Coders who train on modifiers early tend to cut denial rates for practices.

Staying Updated Without Falling Behind

Dermatology coding shifts every year. New CPT codes arrive, definitions expand, and payer edits under NCCI change what can and cannot be billed together. Coders who only rely on memory from last year eventually hit denials.

Updates are easier to manage when they’re broken into routines. Some practices run short “lunch-and-learn” sessions every quarter. Others keep a rolling digital binder with CMS transmittals, AAD coding bulletins, and payer policy alerts. Quick reference sheets work too, especially when shared across teams.

Documentation habits matter as much as code knowledge. Providers who consistently record lesion size, margins, number of specimens, and methods make coding clean. Coders who flag gaps early prevent delays. It’s a partnership, not a one-way street.

Audits should not feel like punishment. A light quarterly audit catches small drifts before they grow. Think of it like a system check on a computer. The goal is smooth operation, not finger pointing.

Technology plays a role. Many practices now use EMR templates that auto-prompt for missing details, anatomic location, number of lesions, closure type. That reduces rework and strengthens compliance.

And resources are always available. CMS, AMA, AAD, specialty blogs, and coding associations update guidance constantly. Following at least two or three of them builds confidence. Coding never stands still, and neither should coders.