Primary Care Coding Alert

Question: If a patient has a pressure ulcer on their back, what is the difference among the stages, for coding purposes?

Missouri Subscriber

Answer: The stages of pressure ulcer represent the healing stages of the wound. If you’re worried about choosing among the stages, don’t be. ICD-10 lays out the characteristics of each stage. And no matter whether the pressure ulcer is located in the right or left upper or lower back; the sacral region; a contiguous site of the back, buttock, and hip or an unspecified part of the back, coded with L89.1- (Pressure ulcer of back) and the appropriate 5th character, you’ll use one of the following 6th characters to document the pressure ulcer stage:

0 (…unstageable). Use this diagnosis code when the stage of the pressure ulcer is undetermined.

1 (… stage 1). Use this diagnosis code for “pressure pre-ulcer skin changes limited to persistent focal edema,” according to ICD-10.

2 (…, stage 2). Use this diagnosis code when the pressure ulcer contain an “abrasion, blister, [or] partial thickness skin loss involving epidermis and/or dermis,” according to ICD-10.

3 (… stage 3). Use this diagnosis code for a pressure ulcer “with full thickness skin loss involving damage or necrosis of subcutaneous tissue,” according to ICD-10.

4 (… stage 4). Use this diagnosis code for a pressure ulcer “with necrosis of soft tissues through to underlying muscle, tendon, or bone,” according to ICD-10.

9 (… unspecified stage). Use this diagnosis code for a pressure ulcer with an unspecified stage. This is different from unstageable, in which the provider notes that the stage cannot be determined.