L98.423 Non-pressure chronic ulcer of back with necrosis of muscle

Billable ICD-10-CM code, FY2026.

Applies from L98.4 Non-pressure chronic ulcer of skin, not elsewhere classified

Applicable to

• Chronic ulcer of skin NOS
• Tropical ulcer NOS
• Ulcer of skin NOS

Excludes2 (not included here)

• pressure ulcer (pressure area) (L89.-)
• gangrene (I96)
• skin infections (L00-L08)
• specific infections classified to A00-B99
• ulcer of lower limb NEC (L97.-)
• varicose ulcer (I83.0-I83.93)

Risk adjustment (HCC)

• CMS-HCC V28: HCC 380 — Chronic Ulcer of Skin, Except Pressure, Through to Bone or Muscle
• CMS-HCC V22: HCC 161 — Chronic Ulcer of Skin, Except Pressure
• RxHCC V08: HCC 311 — Chronic Ulcer of Skin, Except Pressure
• ESRD V24: HCC 161

MS-DRG index

Defines the logic of DRG(s) 573-575 in MDC 09.

Approximate ICD-9-CM (GEMs)

• 707.8 Chronic ulcer of other specified sites (approximate)

Code annotations containing back-references to L98.423

Back-references to L98.42

• Use Additional: E08.622 Diabetes mellitus due to underlying condition with other skin ulcer ("code to identify site of ulcer (L97.1-L97.9, L98.41-L98.49)")
• Use Additional: E09.622 Drug or chemical induced diabetes mellitus with other skin ulcer ("code to identify site of ulcer (L97.1-L97.9, L98.41-L98.49)")
• Use Additional: E10.622 Type 1 diabetes mellitus with other skin ulcer ("code to identify site of ulcer (L97.1-L97.9, L98.41-L98.49)")
• Use Additional: E11.622 Type 2 diabetes mellitus with other skin ulcer ("code to identify site of ulcer (L97.1-L97.9, L98.41-L98.49)")
• Use Additional: E13.622 Other specified diabetes mellitus with other skin ulcer ("code to identify site of ulcer (L97.1-L97.9, L98.41-L98.49)")

Back-references to L98.4

• Use Additional: T65.84 Toxic effect of xylazine ("non-pressure chronic ulcer of skin, not elsewhere classified (L98.4-)")

Diagnosis Index entries for L98.423

• Ulcer, ulcerated, ulcerating, ulceration, ulcerative › back › with › muscle necrosis

Nearby codes

• L98.418 Non-pressure chronic ulcer of buttock with other specified severity
• L98.419 Non-pressure chronic ulcer of buttock with unspecified severity
• L98.42 Non-pressure chronic ulcer of back
• L98.421 Non-pressure chronic ulcer of back limited to breakdown of skin
• L98.422 Non-pressure chronic ulcer of back with fat layer exposed
• L98.423 Non-pressure chronic ulcer of back with necrosis of muscle (this code)
• L98.424 Non-pressure chronic ulcer of back with necrosis of bone
• L98.425 Non-pressure chronic ulcer of back with muscle involvement without evidence of necrosis
• L98.426 Non-pressure chronic ulcer of back with bone involvement without evidence of necrosis
• L98.428 Non-pressure chronic ulcer of back with other specified severity
• L98.429 Non-pressure chronic ulcer of back with unspecified severity