L97.313 maps to CMS-HCC V28 380. A source-labeled RAF reference is available. Confirm the documented diagnosis and applicable coding requirements. MEAT criteria · RAF Calculator · HCC coding software

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Code lookupL97.313

Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Diseases of the skin and subcutaneous tissue (L00-L99) / Other disorders of the skin and subcutaneous tissue (L80-L99)

L97.313

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

Non-pressure chronic ulcer of right ankle with necrosis of muscle

A long-lasting open sore on the right ankle (not from pressure) where the muscle tissue has died and deteriorated.

Buddy Insight

Non-pressure chronic ulcers of the lower extremity are significant indicators of underlying vascular disease, diabetes, or other systemic conditions that impair wound healing.

Overview Risk Models Code Book Documentation Audit Notes Edition comparison

CMS-HCC V28

Mapped

HCC 380

Chronic Ulcer of Skin, Except...

Coefficient HCC 380: 1.078 (Community Non-Dual Aged (CNA))

CMS-HCC V24

Historical

Not used for standard CY2026 Medicare Advantage payment. Select a historical period to review V24.

Not used for CY2026 payment

ACA/HHS

Mapped

HCC 217

HHS-HCC 217 adult, RAF varies...

Code-level coefficient reference

ESRD/PACE

Mapped

HCC 161

Chronic Ulcer of Skin/Except ...

Code-level coefficient reference

RXHCC

Mapped

HCC 311

Chronic Ulcer of Skin, Except...

Code-level coefficient reference

Code Book Path

Official

L97.3Non-pressure chronic ulcer of ankle L97.31Non-pressure chronic ulcer of right ankle L97.313Non-pressure chronic ulcer of right ankle with necrosis of muscle

Inclusion Terms

Official

No inclusion terms are included in this display for L97.313. Check the code and parent instructions in the Code Book.

Excludes 2

Official

certain conditions originating in the perinatal period (P04-P96)Inherited from L00-L99, L97
certain infectious and parasitic diseases (A00-B99)Inherited from L00-L99, L97
complications of pregnancy, childbirth and the puerperium (O00-O9A)Inherited from L00-L99, L97
congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)Inherited from L00-L99, L97
endocrine, nutritional and metabolic diseases (E00-E88)Inherited from L00-L99, L97
lipomelanotic reticulosis (I89.8)Inherited from L00-L99, L97
neoplasms (C00-D49)Inherited from L00-L99, L97
symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)Inherited from L00-L99, L97
systemic connective tissue disorders (M30-M36)Inherited from L00-L99, L97
viral warts (B07.-)Inherited from L00-L99, L97
pressure ulcer (pressure area) (L89.-)Inherited from L00-L99, L97
skin infections (L00-L08)Inherited from L00-L99, L97
specific infections classified to A00-B99Inherited from L00-L99, L97

Related Codes

Official

L97.311Non-pressure chronic ulcer of right ankle limited to breakdown of skin L97.312Non-pressure chronic ulcer of right ankle with fat layer exposed L97.314Non-pressure chronic ulcer of right ankle with necrosis of bone L97.315Non-pressure chronic ulcer of right ankle with muscle involvement without evidence of necrosis L97.316Non-pressure chronic ulcer of right ankle with bone involvement without evidence of necrosis

Includes

Official

chronic ulcer of skin of lower limb NOSInherited from L97
non-healing ulcer of skinInherited from L97
non-infected sinus of skinInherited from L97
trophic ulcer NOSInherited from L97
tropical ulcer NOSInherited from L97
ulcer of skin of lower limb NOSInherited from L97

Excludes 1

Official

No Excludes 1 notes are included in this display for L97.313. Check the code and parent instructions in the Code Book.

Code First

Official

any associated underlying condition, such as:Inherited from L97
any associated gangrene (I96)Inherited from L97
atherosclerosis of the lower extremities (I70.23-, I70.24-, I70.33-, I70.34-, I70.43-, I70.44-, I70.53-, I70.54-, I70.63-, I70.64-, I70.73-, I70.74-)Inherited from L97
chronic venous hypertension (I87.31-, I87.33-)Inherited from L97
diabetic ulcers (E08.621, E08.622, E09.621, E09.622, E10.621, E10.622, E11.621, E11.622, E13.621, E13.622)Inherited from L97
postphlebitic syndrome (I87.01-, I87.03-)Inherited from L97
postthrombotic syndrome (I87.01-, I87.03-)Inherited from L97
varicose ulcer (I83.0-, I83.2-)Inherited from L97

Use Additional

Official

No Use Additional Code instructions are included in this display for L97.313. Check the code and parent instructions in the Code Book.

Code Also

Official

No Code Also instructions are included in this display for L97.313. Check the code and parent instructions in the Code Book.

Buddy Documentation Tip

HCC Buddy guidance

Ulcer site documented as right ankle with clear laterality (right side)

Confirmation that the ulcer is chronic (present for extended duration, not acute)

Etiology documented as non-pressure (e.g., venous stasis, arterial insufficiency, diabetic, or other non-pressure cause)

Clinical assessment of wound depth and tissue involvement

MEAT Support

HCC Buddy guidance

Ulcer site documented as right ankle with clear laterality (right side)

Confirmation that the ulcer is chronic (present for extended duration, not acute)

Etiology documented as non-pressure (e.g., venous stasis, arterial insufficiency, diabetic, or other non-pressure cause)

Clinical assessment of wound depth and tissue involvement

Audit Caution

HCC Buddy guidance

Failing to verify laterality — documentation must specify right ankle; do not assume based on previous encounters

Coding a pressure ulcer code (L89.-) when the ulcer is actually non-pressure in etiology (venous, arterial, diabetic)

Coding muscle necrosis when documentation only states muscle involvement or exposure without confirming necrosis

Confusing 7th character 3 (necrosis of muscle) with 7th character 5 (muscle involvement without necrosis) — necrosis must be explicitly documented

Common Mistakes

HCC Buddy guidance

L97.315 — muscle involvement without necrosis; muscle exposed but viable, no necrosis

L97.314 — necrosis of bone; bone tissue death — most severe

L89.5- — Pressure ulcer codes; use only when ulcer is caused by sustained pressure, not vascular or other non-pressure etiology

Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →

Is L97.313 an HCC code?

Yes. L97.313 (Non-pressure chronic ulcer of right ankle with necrosis of muscle) maps to HCC 380, Chronic Ulcer of Skin, Except Pressure, Through to Bone or Muscle under the CMS-HCC V28 risk adjustment model, with a source-labeled community non-dual aged reference coefficient of 1.078. Source-labeled code-level coefficients are references, not member totals. Actual contribution depends on complete member context, hierarchy and cleanup rules, interactions, and model year. HCC Buddy's RAF Calculator supports CMS-HCC V28 PY2026 and shows no score unless every required source and calculation check passes. It is billable for payment year 2026.

Coder answer: L97.313 is billable and maps to V28 HCC 380, Chronic Ulcer of Skin, Except Pressure, Through to Bone or Muscle. Open it in the Code Book for the tabular path, RAF, and MEAT checklist.

Code: L97.313
Description: Non-pressure chronic ulcer of right ankle with necrosis of muscle
HCC (V28): HCC 380 — Chronic Ulcer of Skin, Except Pressure, Through to Bone or Muscle
RAF reference coefficient: 1.078
Billable: Yes
Payment year: 2026

HCC Category Mapping

V28HCC 380, Chronic Ulcer of Skin, Except Pressure, Through to Bone or Muscle

1.078

ESRDHCC 161, Chronic Ulcer of Skin/Except Pressure

Not separately weighted

RxHCCHCC 311, Chronic Ulcer of Skin, Except Pressure

Not separately weighted

These are source-labeled model coefficients, not member totals. A category may still be removed by hierarchy or model cleanup rules. Weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. Actual per-patient RAF contribution depends on member context, hierarchy and cleanup rules, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains available for historical review.

Work L97.313 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →

MEAT review for L97.313

For L97.313, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule.

MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
EEvaluate: test results, medication response, or physical findings reviewed by the provider
AAssess: explicit mention in the assessment or plan with acknowledgment of status
TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis

Coder workflow notes

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What This Code Means

L97.313 is the ICD-10-CM diagnosis code for non-pressure chronic ulcer of right ankle with necrosis of muscle. A long-lasting open sore on the right ankle (not from pressure) where the muscle tissue has died and deteriorated. L97.313 sits in the ICD-10-CM chapter for diseases of the skin and subcutaneous tissue (l00-l99), within the section covering other disorders of the skin and subcutaneous tissue (l80-l99).

Under the CMS-HCC V28 risk adjustment model, L97.313 maps to Chronic Ulcer of Skin, Except Pressure, Through to Bone or Muscle (HCC 380) with a source-labeled community, non-dual, aged reference coefficient of 1.078. For CY2026 non-PACE Medicare Advantage, CMS uses 100% of the 2024 CMS-HCC model (V28). PACE uses a separate model blend. Source-labeled code-level coefficients are references, not member totals. Actual contribution depends on complete member context, hierarchy and cleanup rules, interactions, and model year. HCC Buddy's RAF Calculator supports CMS-HCC V28 PY2026 and shows no score unless every required source and calculation check passes.

Confirm right ankle laterality and explicit documentation of muscle necrosis before assigning this code. For L97.313, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.

HCC Buddy maintains structured V28 and V24 mapping, source-labeled coefficient references, and MEAT documentation criteria for L97.313 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Confirm right ankle laterality and explicit documentation of muscle necrosis before assigning this code
•This represents significant tissue damage; consider wound care complexity and potential complications in documentation

Clinical Significance

Non-pressure chronic ulcers of the lower extremity are significant indicators of underlying vascular disease, diabetes, or other systemic conditions that impair wound healing. The presence of muscle necrosis indicates severe tissue destruction extending well beyond skin layers, often requiring surgical debridement and signaling significant vascular compromise or uncontrolled systemic disease.

Documentation Requirements

✓Ulcer site documented as right ankle with clear laterality (right side)
✓Confirmation that the ulcer is chronic (present for extended duration, not acute)
✓Etiology documented as non-pressure (e.g., venous stasis, arterial insufficiency, diabetic, or other non-pressure cause)
✓Clinical assessment of wound depth and tissue involvement
✓Documentation of necrotic muscle tissue within the wound bed
✓Clinical or pathological confirmation of muscle necrosis (not just muscle exposure)
✓Wound measurements and staging consistent with deep tissue destruction
✓Treatment plan addressing debridement of necrotic muscle tissue

Commonly Confused Codes

•L97.315: muscle involvement without necrosis; muscle exposed but viable, no necrosis
•L97.314: necrosis of bone; bone tissue death: most severe
•L89.5-: Pressure ulcer codes; use only when ulcer is caused by sustained pressure, not vascular or other non-pressure etiology