Documenting Mohs Surgery

Question:

What should be documented in my note to support billing for Mohs surgery?

Answer:

This is a great question. To support Mohs surgery, comprehensive documentation should include several key components:

Pre-operative Documentation:

• Detailed pathology report confirming the skin cancer diagnosis (basal cell carcinoma, squamous cell carcinoma, etc.)

• Clinical photography showing the lesion's size, location, and characteristics

• Patient history including previous treatments, recurrences, or incomplete excisions

• Documentation of high-risk features (location on face/genitals, size >2cm on trunk/extremities or >1cm on face, aggressive histologic subtypes, perineural invasion)

• Medical necessity justification explaining why Mohs is preferred over standard excision

Operative Documentation:

• Detailed operative report describing the procedure, number of stages required, and final defect size

• Stage-by-stage documentation with tissue mapping and frozen section results

• Real-time photographs of each stage and the final defect

• Pathology reports for each Mohs stage confirming margin status

• Documentation of any complications or unusual findings

Post-operative Documentation:

• Reconstruction plan and methods used for wound closure

• Post-operative care instructions and follow-up schedule

• Final pathology confirming complete tumor removal

• Patient education materials provided

Insurance and Administrative:

• Prior authorization if required by the insurance plan

• Appropriate CPT codes (17311-17315 for Mohs surgery stages, plus reconstruction codes)

• Documentation supporting medical necessity, particularly for lesions that might be considered for standard excision

This thorough documentation ensures proper patient care, supports insurance reimbursement, and provides a complete medical record for future reference.

*This response is based on the best information available as of 8/28/25.

Measuring an ED&C

Question:

How are measurements determined for electrodessication and curettage (ED&C) procedures for destruction of malignant lesions CPT codes 17260-17286? Is it the lesion only or the lesion after curettage?

Answer:

Great question—this detail can make a big difference in accurate coding. For CPT codes 17260–17286, which describe destruction of malignant skin lesions (including methods like electrodessication and curettage), the measurement is based on the lesion diameter prior to the procedure, not the size of the wound or defect after curettage.

Here’s what’s key:

• Measure the lesion itself before any destruction technique is applied.

• Do not measure the post-procedure defect or area of tissue removed.

• The method of destruction (e.g., ED&C, cryosurgery, laser) does not affect code selection—only anatomic location and lesion size matter.

*This response is based on the best information available as of 8/14/25.

I&D for Cutaneous Abscess

Question:

I am new to Dermatology coding and need help with this procedure note: An I&D was performed on the left hand for a cutaneous abscess. Consent was obtained and risks were reviewed including but not limited to delayed wound healing, infection, need for multiple I and D's, and pain. The area was prepped in the usual clean fashion. Local anesthesia was achieved with 2 cc of 1% carbocaine. The abscess was incised with a 15 blade, and pressure was applied to the wound to drain the underlying contents. Aquaphor and a dry sterile dressing were applied and wound care was reviewed. Can you tell me what CPT code I should use?

Answer:

Welcome to Dermatology coding! We are happy to help you. In this note, the physician is performing an incision and drainage. The physician incised the abscess and drained the abscess. Typically, a simple I&D involves a single lesion or abscess just below the skin’s surface. The correct CPT code to report is 10060 (incision and drainage of abscess) and the diagnosis code is L02.512 (Cutaneous abscess of left hand).

*This response is based on the best information available as of 7/31/25.

Wart Destruction with Liquid Nitrogen

Question:

I saw an established patient who I see for evaluation of a wart on the arm. The wart is moderate in severity. I evaluated the wart, performed a skin exam and removed the wart with liquid nitrogen and told the patient to come back PRN. My coder tells me I can only report the wart destruction and not a visit code. Is that correct?

Answer:

It appears the focus of the visit is the removal of the wart (17110). Unless you have a significant separately identifiable E/M service, the E/M service would be inherent to the procedure. Keep in mind the procedure includes pre-service work which is the E/M service. Only the procedure should be reported in the situation you described.

*This response is based on the best information available as of 7/17/25.

Cancer Surveillance E/M

Question:

My physician saw an established patient for follow-up in the office for cancer surveillance. The patient is doing well and no treatment is indicated. In addition, the physician removes a benign lesion on the right anterior neck (1.1 cm) and the patient is being treated for a rash that is acute. The physician recommends cleansers and moisturizers and prescribes a topical steroid. What codes should be billed?

Answer:

An E/M is supported for cancer surveillance and treating the rash. The problems addressed are low complexity (1 acute uncomplicated and 1 stable chronic) with moderate risk (prescription drug management). The level supported is 99213-25. CPT code 11422 is reported for the benign lesion excision on the right anterior neck.

*This response is based on the best information available as of 7/03/25.

Aquaphor and UVB Billing

Question:

Some of our dermatology physicians use Aquaphor as a conductive agent when doing UVB for our psoriasis patients and billing CPT code 96910. We see that Aquaphor is not considered a conductive agent, but we wanted to get your feedback to make sure. Should we use CPT code 96910 or 96912?

Answer:

First, Aquaphor is not a conductive agent.  It is very clear from the CPT guidance that 96910 (photochemotherapy) is reported with tar and ultraviolet B rays (Goeckerman treatment) or petrolatum and ultraviolet B rays. If you use Psolarens, the correct code to report is 96912.   If other substances or no substance is used, you report 96900 (Actinotherapy (ultraviolet light)).  Aquaphor would fall into that category.  

*This response is based on the best information available as of 6/19/25.