Coding for Burns
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. The likelihood for a medical coder to have to code a burn case is extremely high. Here’s what you need to know.
A burn is tissue damage with partial or complete destruction of the skin caused by heat, chemicals, electricity, sunlight, or nuclear radiation. Proper selection of burn codes requires consideration of the location of the burn, severity, extent, and external cause in addition to laterality and encounter. ICD-10 makes a distinction between burns and corrosions:
- Burn codes apply to thermal burns (except sunburns) that come from a heat source, such as fire, hot appliance, electricity, and radiation.
- Corrosions are burns due to chemicals.
Burn severity is classified based on the depth of the burn. There are six degrees of burns:
- First-degree burns damage the outer layer (epidermis) of the skin; erythema
- Second-degree burns indicate blistering with damage extending beyond the epidermis partially into the layer beneath it (dermis)
- Third-degree burns indicate full-thickness tissue loss with damage or complete destruction of both layers of skin (including hair follicles, oil glands, & sweat glands)
ICD-10 Coding Using the “Rules of Nines”
You need at least three codes to properly report burn diagnoses:
First-listed code(s): S/S for site and severity (categories T20-T25)
- Your first-listed code will be a combination code that reports both the site and severity of the injury. The descriptions of codes in the T20-T28 range are first defined by an anatomical location of the body affected by burn or corrosion.
- 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 reports additional details regarding the anatomical site of the burn.
- The sixth character represents laterality.
Next listed code: E for extent (categories T31/32)
- Burns and corrosions are classified according to the extent, or percentage, of the total body surface area involved (TBSA).
- Code T31 to report a burn and T32 to report corrosion, based on the classic “rule of nines.”
- The rule of nines, for adult patients, assigns 1% of TBSA to the genitalia, and multiples of 9% to other body areas (9% head, 9% per arm, 18% per leg, etc.).
- A modified rule of nines is applied for infants, to account for their relatively larger head (18%) and smaller legs (14%, 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 that is suffering from third-degree burns or corrosions only.
Lastly, code(s): E for external cause code(s)
- External Cause – To identify the source, place, and intent of the burn.
- Agent – To identify the chemical substance of the corrosion.
ICD-10-CM guidelines recommend reporting appropriate external cause codes for burn patients. Not all payers accept these codes, however.
CPT Coding Using the Lund-Browder Classification
CPT codes to report local treatment of burns and many skin grafting procedure codes, specify the surface area (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 for easy TBSA calculation by body area and patient age.