Corros 90%/more of body surfc w 0% to 9% third degree corros

This code describes a severe, widespread chemical or thermal injury affecting 90% or more of the patient's total body surface area. While the overall body surface involvement is extensive, the most severe (third-degree) damage is limited to less than 10% of the total affected area. The remaining extensive injury is typically superficial or partial thickness.

This code is appropriate for patients presenting with massive corrosive injuries, such as those from large-scale chemical spills or extensive flame burns, where nearly the entire body is affected. It specifically applies when the majority of these extensive burns are not full-thickness, but rather superficial or partial-thickness, with only a small percentage reaching the deepest tissue layers.

• Always sequence this code first when multiple corrosion codes are applicable, as it represents the highest percentage of body surface involvement.
• Ensure documentation clearly specifies both the total body surface area affected and the percentage of third-degree involvement to justify this specific code.
• Do not use this code if the third-degree corrosion component is 10% or more of the total body surface area, even if overall involvement exceeds 90%.