What is ICD-10 code L98.426?

L98.426 is the ICD-10-CM diagnosis code for Non-pressure chronic ulcer of back with bone involvement without evidence of necrosis. A long-lasting open sore on the back that is not caused by pressure, with bone involvement but without dead tissue. L98.426 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. L98.426 is part of the FY2026 ICD-10-CM code set published by the CMS National Center for Health Statistics and used on Medicare, Medicaid, and commercial claims in the United States.

Yes. L98.426 is a billable ICD-10-CM code that can be reported on professional and institutional claims as a primary or secondary diagnosis when the provider documentation supports the specific condition described. Billable codes in ICD-10-CM are coded to the highest level of specificity available for the documented diagnosis. L98.426 is current for fiscal year 2026 and remains in the active CMS ICD-10-CM code set published by the National Center for Health Statistics.

What is the V28 vs V24 difference for L98.426?

CMS phased in the V28 risk adjustment model over payment years 2024 (33%), 2025 (67%), and 2026 (100%), replacing V24. V28 consolidates HCC categories, removes some lower-acuity conditions, and recalibrates RAF weights across the entire model. For L98.426, V28 maps to Chronic Ulcer of Skin, Except Pressure at RAF 0.426 while V24 mapped to Chronic Ulcer of Skin, Except Pressure at RAF 0.426. Both models can still appear in legacy data and in payer-specific lookback periods.

What should coders know when reporting L98.426?

Bone involvement without necrosis indicates exposed but viable bone; distinguish from L98.424 Imaging or surgical exploration findings should support bone involvement documentation Because L98.426 maps to a payment HCC, the documentation must also satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's risk adjustment score.

L98.426 ICD-10 Code: Non-pressure chronic ulcer

ICD-10-CM Code View

HCC Buddy Code Card

Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.

Code lookupL98.426Effective 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)

L98.426

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

Non-pressure chronic ulcer of back with bone involvement without evidence of necrosis

A long-lasting open sore on the back that is not caused by pressure, with bone involvement but without dead tissue.

Buddy Insight

Non-pressure chronic ulcers of the back with deep tissue involvement (without necrosis) indicate significant wound depth requiring specialized wound care and monitoring.

CMS-HCC V28

Mapped

HCC 380

Chronic Ulcer of Skin, Except...

RAF 0.426

CMS-HCC V24

Mapped

HCC 161

Chronic Ulcer of Skin, Except...

RAF 0.426

ACA/HHS

Not risk-adjusted for this model/period.

RAF 0

ESRD/PACE

Mapped

HCC 161

Chronic Ulcer of Skin, Except...

RAF 0.0

RXHCC

Mapped

HCC 311

Diabetic and Chronic Skin Ulcer

RAF 0.0

Code Trumping

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Compare selected patient codes to show trumped or trumps impact.

Code Book Path

Official

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

L98.42Non-pressure chronic ulcer of back

L98.426Non-pressure chronic ulcer of back with bone involvement without evidence of necrosis

Inclusion Terms

Official

ICD-10-CM does not list inclusion terms for L98.426 in this effective period.

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for L98.426 in this effective period.

Related Child Codes

Official

L98.421Non-pressure chronic ulcer of back limited to breakdown of skin

L98.422Non-pressure chronic ulcer of back with fat layer exposed

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

L98.424Non-pressure chronic ulcer of back with necrosis of bone

L98.425Non-pressure chronic ulcer of back with muscle involvement without evidence of necrosis

Includes

Official

ICD-10-CM does not list Includes notes for L98.426 in this effective period.

Excludes 1

Official

ICD-10-CM does not list Excludes 1 notes for L98.426 in this effective period.

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for L98.426 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for L98.426 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for L98.426 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

Provider documentation of the ulcer as chronic (present for extended duration, not acute)

Anatomical location clearly specified as back

Confirmation that the ulcer is non-pressure in etiology (e.g., venous, arterial, inflammatory, or other documented cause)

Description of wound bed characteristics and tissue involvement depth

MEAT Support

HCC Buddy guidance

Provider documentation of the ulcer as chronic (present for extended duration, not acute)

Anatomical location clearly specified as back

Confirmation that the ulcer is non-pressure in etiology (e.g., venous, arterial, inflammatory, or other documented cause)

Description of wound bed characteristics and tissue involvement depth

Audit Caution

HCC Buddy guidance

Confusing non-pressure ulcers (L97/L98) with pressure ulcers (L89) — etiology must be clearly documented as non-pressure related

Failing to query the provider when severity/depth is not clearly documented, defaulting to unspecified codes unnecessarily

Upgrading to necrosis code (digit 4) when bone is involved but viable — absence of necrosis must be coded with the '6' suffix

Not coding the underlying etiology (e.g., venous insufficiency, peripheral arterial disease) as an additional diagnosis when documented

Common Mistakes

HCC Buddy guidance

L89.1xx — Pressure ulcer of back; use when ulcer is caused by sustained pressure from lying in bed

L98.41x — Non-pressure chronic ulcer of buttock; differs by anatomical location (buttock vs. back)

L98.49x — Non-pressure chronic ulcer of other sites; use when location is neither back, buttock, nor other specified sites

L97.x — Non-pressure chronic ulcer of lower leg; different anatomical site entirely

Last updated: FY2026 ICD-10-CM Apr update, Apr 1, 2026 through Sep 30, 2026. CMS-HCC V28 is 100% phased in for payment year 2026.

Is L98.426 an HCC code?

Yes. L98.426 maps to Chronic Ulcer of Skin, Except Pressure under the CMS-HCC V28 risk adjustment model (and Chronic Ulcer of Skin, Except Pressure under V24).

HCC Category Mapping

V28HCC 380, Chronic Ulcer of Skin, Except Pressure

0.426

V24HCC 161, Chronic Ulcer of Skin, Except Pressure

0.426

ESRDHCC 161, Chronic Ulcer of Skin, Except Pressure

0.000

RxHCCHCC 311, Diabetic and Chronic Skin Ulcer

0.000

RAF weights shown are the community, non-dual, aged base weights from the CMS risk adjustment model file. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.

MEAT Criteria for L98.426

For L98.426to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically, it has to be re-documented and supported each calendar year.

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

Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed L98.426 during that encounter, not just copy-forwarded from a problem list.

What This Code Means

L98.426 is the ICD-10-CM diagnosis code for non-pressure chronic ulcer of back with bone involvement without evidence of necrosis. A long-lasting open sore on the back that is not caused by pressure, with bone involvement but without dead tissue. L98.426 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, L98.426 maps to Chronic Ulcer of Skin, Except Pressure (HCC 380) with a community, non-dual, aged base RAF weight of 0.426. The V24 model used during the PY2024–PY2025 transition mapped L98.426 the same way and at the same RAF weight. V28 is the CMS-HCC risk adjustment model that reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition.

Bone involvement without necrosis indicates exposed but viable bone; distinguish from L98.424. Because L98.426 maps to a payment HCC, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's Medicare Advantage risk adjustment score. 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, RAF weights, and MEAT documentation criteria for L98.426 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Bone involvement without necrosis indicates exposed but viable bone; distinguish from L98.424
•Imaging or surgical exploration findings should support bone involvement documentation

Clinical Significance

Non-pressure chronic ulcers of the back with deep tissue involvement (without necrosis) indicate significant wound depth requiring specialized wound care and monitoring. While the tissue remains viable, the depth of involvement signals ongoing risk for progression to necrosis and potential complications. Accurate coding of the tissue involvement level is essential for appropriate risk adjustment and care planning.

Documentation Requirements

✓Provider documentation of the ulcer as chronic (present for extended duration, not acute)
✓Anatomical location clearly specified as back
✓Confirmation that the ulcer is non-pressure in etiology (e.g., venous, arterial, inflammatory, or other documented cause)
✓Description of wound bed characteristics and tissue involvement depth
✓Imaging confirming bone involvement without evidence of necrosis
✓Documentation that exposed bone tissue remains viable
✓Wound measurements (length, width, depth) and assessment of wound edges and surrounding tissue
✓Current treatment plan including wound care interventions

Commonly Confused Codes

•L89.1xx: Pressure ulcer of back; use when ulcer is caused by sustained pressure from lying in bed
•L98.41x: Non-pressure chronic ulcer of buttock; differs by anatomical location (buttock vs. back)
•L98.49x: Non-pressure chronic ulcer of other sites; use when location is neither back, buttock, nor other specified sites
•L97.x: Non-pressure chronic ulcer of lower leg; different anatomical site entirely
•L98.424: Same site with necrosis of bone; use when bone tissue is dead/necrotic, not merely involved