Chronic Skin Ulcer (Non-Pressure) ICD-10-CM codes

Category L97 covers chronic ulcers of the lower limb and L98.4- covers the buttock, back, abdomen, chest, neck, face, groin and other sites. Each code has three axes: site (4th character), laterality (5th character), and severity (6th character). The severity values are 1 limited to breakdown of skin, 2 with fat layer exposed, 3 with necrosis of muscle, 4 with necrosis of bone, 5 with muscle involvement without necrosis, 6 with bone involvement without necrosis, 8 other specified severity, and 9 unspecified severity. An ulcer of the right heel with exposed fat is L97.412.

L97 and L98.4 have a code-first note and are almost always secondary codes. For a diabetic foot ulcer, sequence the diabetes combination code first (E11.621 for a type 2 diabetic foot ulcer, E11.622 for a diabetic ulcer at another skin site, or the E10 equivalent), then the L97 code for site and depth. For venous ulcers, code first I87.2 (venous insufficiency), I87.3- (chronic venous hypertension with ulcer, such as I87.331) or I83.0- (varicose veins with ulcer), followed by L97. Arterial ulcers from atherosclerosis use I70.23- or I70.24- first, then L97.

Gangrene, when documented, is sequenced ahead of the ulcer with I96. Do not use L97 for pressure ulcers (L89), skin ulcers of the genital organs, or ulcers described as acute wounds or postoperative wound breakdown, which are injury and complication codes. The severity documentation can come from wound-care staff, but the diagnosis of the ulcer and its cause must come from the provider.