Consider Depth and Other Factors when Coding for Burns
- By Stacy Chaplain
- In Coding
- August 12, 2019
- Comments Off on Consider Depth and Other Factors when Coding for Burns

The more familiar you are with burn injuries and documentation, the easier it is to code the cases.
Burn coding is challenging and requires you to consider multiple factors. Proper coding and documentation require an understanding of the types of burns, estimating burn extent based on age, and being familiar with how this estimation varies when coding for ICD-10-CM or CPT®.
Approximately every minute, someone in the United States sustains a burn injury serious enough to require treatment. According to the American Burn Association, an estimated 486,000 hospital admissions and visits to hospital emergency departments occur annually for burn evaluation and treatment in the United States. This statistic does not account for burn injuries treated in hospital clinics, private medical offices, or community health centers. The likelihood for a medical coder to code a burn case is extremely high. Here’s what you need to know.
How do you Define a Burn?
A burn is tissue damage with partial or complete destruction of the skin caused by heat, chemicals, electricity, sunlight, or nuclear radiation. Scalds from hot liquids and steam, building fires, and flammable liquids and gases are the most common causes of burns. Inhalation injury, another type of burn, results from breathing smoke. Keep in mind, ICD-10-CM differentiates between burns and corrosions; however, the ICD-10-CM guidelines are the same for both.
Types of Burns
- Thermal burns are caused by an external heat source such as fire or hot liquids in direct contact with the skin, causing tissue cell death or charring.
- Electrical burns happen when the body makes contact with an electric current. Electrical burns can be more extensive than what is seen externally, often affecting internal tissues and muscles.
- Radiation dermatitis is a type of dermatitis resulting from exposure of the skin, eyes, or internal organs to types of radiation. Causes include exposure from sources such as Cobalt therapy, fluoroscopy, welding arcs, sun exposure, and tanning bed lights.
- Corrosions are chemical burns due to contact with internal or external body parts caused by strong acids such as bleach and battery fluid, or strong bases (alkalis) such as ammonia, detergents, or solvents.
Burns are defined by how deep they are and how large an area they cover. A large burn injury is likely to include burned areas of different depths. Deep burns heal more slowly, are more difficult to treat, and are prone to complications such as infections and scarring.
Degrees of Burns
Burn severity is classified based on the depth of the burn. There are six degrees of burns (see Figure 1 for corresponding skin depth):
- First-degree burns damage the outer layer (epidermis) of the skin. These burns are usually dry, red (erythematous), and painful and usually heal on their own within a week. A common example is a sunburn.
- Second-degree burns indicate blistering with damage extending beyond the epidermis partially into the layer beneath it (dermis). When severe, these burns might necessitate a skin graft — natural or artificial skin to cover and protect the body while it heals — and they may leave a scar.
- Third-degree burns indicate full-thickness tissue loss with damage or complete destruction of both layers of skin (including hair follicles, oil glands, and sweat glands). These burns always require skin grafts.
- Fourth-degree burns extend into fat.
- Fifth-degree burns extend into the muscle.
- Sixth-degree burns extend damage down to the bone.
Many patients suffer from burns in multiple anatomical locations. When coding these cases:
- Assign a separate code for each location with a burn.
- If a patient has multiple burns on the same anatomical site, select the code that reflects the most severe burn for that location.
- Sequence the codes in order of severity, with the most severe burn listed first.
When a patient has both internal and external burns/corrosions, the circumstances of admission govern the selection of the principal diagnosis (i.e., first-listed diagnosis).
When a patient is admitted for burn injuries and other related conditions, such as smoke inhalation and/or respiratory failure, the circumstances of admission govern the selection of the principal diagnosis.
Code Using the Rule of Nines
ICD-10 burn codes are reported by body location, depth, extent, and external cause, including the agent or cause of the corrosion, as well as laterality and encounter. To code burn cases correctly, specify the site, severity, extent, and external cause.
You need at least three codes to properly report burn diagnoses:
- First-listed code(s): Site and severity (from categories T20-T25)
- Your first-listed code will be a combination code that reports both the site and severity of the injury. The site refers to the anatomical location that is affected by the burn or corrosion. Code descriptions in the T20-T28 range first define a general part or section of the human body.
- The fourth character for each category identifies the severity (except categories T26-T28). Using the layers of the skin, the severity of a burn is identified by degree.
- The fifth character enables you to report additional details regarding the anatomical site of the burn.
- The sixth character represents laterality.
- Next-listed code: Extent (from code category T31/T32)
- Burns and corrosions are classified according to the extent or percentage of the body surface involved.
- Total body surface area (TBSA) involved is reported using a code from T31 for a burn or T32 for corrosion, based on the classic “rule of nines,” as shown in Figure 2.
- The rule of nines for adult patients assigns 1 percent of TBSA to the genitalia and multiples of 9 percent to other body areas (9 percent for the head, 9 percent per arm, 18 percent per leg, etc.).
- A modified rule of nines is applied for infants to account for their relatively larger head (18 percent) and smaller legs (14 percent, each).
- The required fourth character identifies the percentage of the patient’s entire body affected by burns.
- The fifth character identifies the percentage of the patient’s body suffering from third-degree burns or corrosions only.
- Additional code(s): External cause code(s)
ICD-10-CM guidelines recommend reporting appropriate external cause codes for burn patients. Not all payers accept these codes, however.
- External cause – To identify the source, place, and intent of the burn.
- Agent – To identify the chemical substance of the corrosion.
CPT® Coding with Lund-Browder Classification
Codes to report local treatment of burns, and many skin grafting procedure codes, specify the TBSA treated. CPT® utilizes the more precise Lund-Browder classification method to calculate TBSA for burns and grafts. Lund-Browder divides the body into 19 distinct areas and specifies six different age groups to account for the changes in body composition during development into adulthood.
The CPT® code book contains a Lund-Browder classification method chart, as shown in Table 1, for easy TBSA calculation by body area and patient age.
Table 1 Lund-Browder Classification Method Chart
Area | Birth-1 year | 1-4 years | 5-9 years | 10-14 years | 15 year | Adult | 2nd degree | 3rd degree | Total | Donor areas |
Head | 19% | 17% | 13% | 1% | 9% | 7% | ||||
Neck | 2% | 2% | 2% | 2% | 2% | 2% | ||||
Anterior trunk | 13% | 13% | 13% | 13% | 13% | 13% | ||||
Posterior trunk | 13% | 13% | 13% | 13% | 13% | 13% | ||||
Right buttock | 2.5% | 2.5% | 2.5% | 2.5% | 2.5% | 2.5% | ||||
Left buttock | 2.5% | 2.5% | 2.5% | 2.5% | 2.5% | 2.5% | ||||
Genitalia | 1% | 1% | 1% | 1% | 1% | 1% | ||||
Right upper arm | 4% | 4% | 4% | 4% | 4% | 4% | ||||
Left upper arm | 4% | 4% | 4% | 4% | 4% | 4% | ||||
Right lower arm | 3% | 3% | 3% | 3% | 3% | 3% | ||||
Left lower arm | 3% | 3% | 3% | 3% | 3% | 3% | ||||
Right hand | 2.5% | 2.5% | 2.5% | 2.5% | 2.5% | 2.5% | ||||
Left hand | 2.5% | 2.5% | 2.5% | 2.5% | 2.5% | 2.5% | ||||
Right thigh | 2.5% | 6.5% | 1% | 8.5% | 9% | 9.5% | ||||
Left thigh | 5.5% | 6.5% | 2% | 8.5% | 9% | 9.5% | ||||
Right leg | 5% | 5% | 5.5% | 6% | 6.5% | 7% | ||||
Left leg | 5% | 5% | 5.5% | 6% | 6.5% | 7% | ||||
Right foot | 3.5% | 3.5% | 3.5% | 3.5% | 3.5% | 3.5% | ||||
Left foot | 3.5% | 3.5% | 3.5% | 3.5% | 3.5% | 3.5% | ||||
Total |
Determining a CPT® code for burn treatment requires documentation of the degree of the burn and the percentage of body area affected. Documenting what is done during the visit is important because burn coding can be used for a dressing change or debridement.
Typical CPT® procedure codes include:
16000 Initial treatment, first degree burn, when no more than local treatment is required
16020 Dressings and/or debridement of partial-thickness burns, initial or subsequent; small (less than 5% total body surface area)
16025 medium (e.g., whole face or whole extremity, or 5% to 10% of total body surface area)
16030 large (e.g., more than 1 extremity, or greater than 10% of total body surface area)
Note: CPT® code 16000 is for initial treatment of first-degree burns only, whereas codes 16020, 16025, and 16030 are for initial and subsequent visits for treatment of second- and third-degree burns.
Burn treatment codes can be used in addition to an office visit; however, the office visit must be medically necessary and modifier 25 Significant, separately identifiable evaluation and management service by the same physician other qualified health care professional on the same day of the procedure or other service must be appended to the office visit. A separate, medically necessary office visit might occur; for example, to prescribe medications such as topical ointments, antibiotics, and pain medications.
Let’s apply these rules with a case scenario:
Example: A 35 y/o cook presents with a second-degree burn to the front of the left forearm, first-degree burns to multiple sites on the anterior head, face, and neck, and a third-degree burn of the anterior chest from bubbling hot oil. He states he was preparing one of his signature dishes and accidentally poured too much cooking oil into the hot skillet, which splashed up and burned him. This is his first visit for evaluation of his burns. Debridement and dressings were applied to the areas affected by second- and third-degree burns.
Always sequence first the diagnosis code that reflects the highest degree of burn: T21.31XA Burn of third degree of chest wall, initial encounter, T22.212A Burn of second degree of left forearm, initial encounter, T20.19XA Burn of first degree of multiple sites of head, face, and neck, initial encounter.
For extent, add up the anterior left arm (4.5 percent), anterior head and neck (4.5 percent), and anterior trunk (18 percent), which makes the TBSA burned 27 percent using the rule of nines. The fourth digit of the code indicates TBSA (27 percent) and the fifth digit indicates the percentage of the body that has received third-degree burns (18 percent), so the code indicating extent is T31.21 Burns involving 20-29% of body surface with 10-19% third degree burns.
Lastly, external cause codes are: X10.2XXA Contact with fats and cooking oils, initial encounter and Y92.511 Restaurant or cafe as the place of occurrence of the external cause.
For coding the treatment, Lund-Browder Classification estimates the total burn area to be treated at 16 percent, including the partial thickness, left forearm burn (3 percent) and the full thickness anterior chest burn (13 percent). The first-degree burn will be erythematous but will not require anything more than local treatment. CPT® code 16030 indicates dressings and/or debridement of a large burn (e.g., more than 1 extremity, or greater than 10 percent TBSA).
Resource
American Burn Association, Scald Statistics, and Data Resources
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