Calculating your Lesion and Wound Coding

How are you doing with your Lesion and Wound Repair Coding? Many Physicians across specialties perform skin procedures so it’s important that we understand the proper coding and documentation required.

Knowing the guidelines for Lesion Excision and Wound Repair is crucial because at times they are bundled and the calculation methods are very different. Let’s start with Lesion excision.

Lesion Excision: Do the Math

Yes, Lesion excision may require math. You need the margins and the largest diameter excised documented by your Physician. This needs to happen prior to sending it off to pathology. 

Why? Well, what happens when a sample goes to pathology it may shrink. It’s definitely better to have some measurements so if you have to use path, and that’s all you have, well you need a measurement but it will be more accurate if documented prior to excision measurements taken prior to excision. 

What do you need before you start?

Is it Benign or Malignant? This changes the code set as for Benign you are looking at 11400-11446 and if Malignant 11600-11646. 

Location, Location, Location. The sites are all described in each main code 11400,11420,11440 and so you need to know where the site belongs code-wise.

Size is Crucial! Your code will change based on cm and so you need to do the calculation. You have to add margins on both sides with the largest diameter of the lesion so let’s take a 3 cm excised diameter. 

Then you take your physician’s documentation of margins, which typically is 1.5 on each side but can be smaller like .5cm. So for instance: You have 1.5 on each side and that totals 3cm. You will add 3cm +1.5+1.5=6cm 

Code each Lesion Separate. Yes, you code them all individually. What do we do when our measurements are in mm and cm?

Like I said, let’s do the math. I will show you an example

The patient presents to the physician for the removal of a squamous cell carcinoma of the right cheek. After the area is prepped and draped in a sterile fashion the surgeon measured the lesion and documented the size of the lesion as 2.3 cm at its largest diameter. Additionally, the physician took margins of 2 mm on each side of the lesion. Single layer closure was performed. The patient tolerated the procedure well.

I have highlighted our key points. Here is the math:

 2.3cm +(2mm +2mm=.4cm)=2.7cm

Does the question remain what if I do not get the margins? If you do not have margins we follow basic guidelines in CPT®.

For instance, if the document reads that the excision was for a 3 x 2 cm lesion, then you code the largest diameter of 3 cm which is the only measurement you can use without margins. Per CPT®  “Code selection is determined by measuring the greatest clinical diameter of the  lesion plus that [most narrow] margin required for complete excision.” I hope that helps clear up confusion.

Close the Gap in Wound repair Coding

Next, we come to the repair or closure. There are times when a lesion excision or an open wound needs to be closed after a procedure and we need to know when that is billable. 

Per the guidelines: “The excision of benign lesions includes simple repair. If the wound requires (layered) closure, intermediate, see 12051–12057; complex, see 13151–13153.” CPT®

Before we look at the steps let’s review some of the guideline changes for 2022. 

The guidelines for a simple repair were revised to clarify a  wound closure done with sutures, staples, or tissue adhesives or as an example, 2-cyanoacrylate or Dermabond type. It clarifies that it can be done as a single option or in combination with other closure methods listed to be a simple repair. Any other type of Chemical cauterization, electrocauterization, or wound closure using adhesive strips as the only repair material is coded with an Evaluation and Management code.

As mentioned we have steps just like in lesion excision for proper coding but make sure you pay attention to the layers. When it says “layered closure” it means the layers of skin so if it’s more than the simple layers of skin such as the Dermis or Epidermis and goes deeper into Subcutaneous and Fascia you have layers that constitute Intermediate. 

So we know simple closure is not billable with other procedures but you can bill it if that’s all you are doing at that site. Let’s look at the steps.


Complexity: Is it Simple, Intermediate, or Complex?

Location: What site is repaired? Just like lesion excision, the codes are grouped into location areas.

Size: Codes are based on cm and have a range of measurements.

How do you calculate? Well, we have to take the wounds of the same complexity and location grouping and add them up to fit them into the correct code calculation. This is different from lesion excision where we code each separately. You can have multiple closure codes with different complexities. 

Let’s look at an example:

The patient presents to the emergency department with multiple lacerations from a knife fight at the local bar. After examination, it was determined these lacerations could be closed using local anesthesia. The areas were prepped and draped in the usual sterile fashion. The surgeon documented the following closures: 7.6 cm simple closure of the right forearm; 5.7 cm intermediate closure of the upper right arm; 4.7 cm complex closure of the right neck; 10.3 cm intermediate closure of the upper chest

We have a  simple closure of 7.6cm for the right forearm which is reported with  12004. We also have a new complexity of intermediate closure on the arm of 5.7 cm and the upper chest of 10.3 cm. The (chest) and the extremities (arm) are in the same anatomic code set and are both the same complexity of intermediate, so we add them up for a  total of 16 cm and use code 12035. Finally, we have a  complex repair of the neck, 4.7 cm which is  13132.

You will want to read the guidelines carefully and the parenthetical notes in order to capture all coding opportunities.  There are many other code sets such as debridement and lesion excision that can be reported together with wound repair in certain circumstances.  

Always check your LCD policies and insurance coverage guidelines when reporting these codes. It may be helpful to review them and provide education to your physician so they can be aware and document to the proper specificity. 

It can be complex but when you break it down and keep things organized you can do it!

Surgery coding is complex so if your facility is in need of specialty reviews. Please contact

CPT® is a registered trademark of the American Medical Association.

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