E71.520 ICD-10-CM Code: Childhood cerebral X-linked adrenoleukodystrophy
HCC Buddy Code Card
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FY 2026 Apr update / Endocrine, nutritional and metabolic diseases (E00-E89) / Metabolic disorders (E70-E88)
E71.520
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceChildhood cerebral X-linked adrenoleukodystrophy
A genetic disorder affecting males where the nervous system progressively deteriorates during childhood due to accumulation of fatty acids, causing behavioral changes, learning problems, and loss of motor control.
Buddy Insight
Childhood cerebral X-linked adrenoleukodystrophy is the most devastating form of X-linked adrenoleukodystrophy, typically presenting in boys aged 4-8 years with behavioral changes, declining school performance, and progressive demyelination of the cerebral white matter.
CMS-HCC V28
00
RAF 0
CMS-HCC V24
MappedHCC 23
RAF 0.230
ACA/HHS
00
RAF 0
ESRD/PACE
MappedHCC 23
RAF 0.0
RXHCC
MappedHCC 43
RAF 0.0
Code Trumping
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Code Book Path
Inclusion Terms
OfficialICD-10-CM does not list inclusion terms for E71.520 in this effective period.
Excludes 2
OfficialICD-10-CM does not list Excludes 2 notes for E71.520 in this effective period.
Related Child Codes
Includes
OfficialICD-10-CM does not list Includes notes for E71.520 in this effective period.
Excludes 1
OfficialICD-10-CM does not list Excludes 1 notes for E71.520 in this effective period.
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for E71.520 in this effective period.
Use Additional
OfficialICD-10-CM does not list Use Additional Code instructions for E71.520 in this effective period.
Code Also
OfficialICD-10-CM does not list Code Also instructions for E71.520 in this effective period.
Buddy Documentation Tip
MEAT Support
Audit Caution
Common Mistakes
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 E71.520 an HCC code?
Yes. E71.520 maps to Other Significant Endocrine and Metabolic Disorders under the V24 model but is not retained in V28.
HCC Category Mapping
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 E71.520
For E71.520to 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 E71.520 during that encounter, not just copy-forwarded from a problem list.
What This Code Means
E71.520 is the ICD-10-CM diagnosis code for childhood cerebral x-linked adrenoleukodystrophy. A genetic disorder affecting males where the nervous system progressively deteriorates during childhood due to accumulation of fatty acids, causing behavioral changes, learning problems, and loss of motor control. E71.520 sits in the ICD-10-CM chapter for endocrine, nutritional and metabolic diseases (e00-e89), within the section covering metabolic disorders (e70-e88).
Under the older CMS-HCC V24 model, E71.520 maps to Other Significant Endocrine and Metabolic Disorders (HCC 23) with a community, non-dual, aged base RAF weight of 0.230. 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.
This X-linked condition primarily affects males; document age of onset (typically 4-8 years) and progression of neurological symptoms. Because E71.520 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 E71.520 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This X-linked condition primarily affects males; document age of onset (typically 4-8 years) and progression of neurological symptoms
- •Differentiate from adolescent form (E71.521) by age of symptom onset; childhood form has earlier presentation and more rapid progression
Clinical Significance
Childhood cerebral X-linked adrenoleukodystrophy is the most devastating form of X-linked adrenoleukodystrophy, typically presenting in boys aged 4-8 years with behavioral changes, declining school performance, and progressive demyelination of the cerebral white matter. Without intervention, rapid neurological deterioration leads to vegetative state and death within 2-5 years of symptom onset. Hematopoietic stem cell transplantation in early stages can halt progression.
Documentation Requirements
- ✓Document age of symptom onset, MRI findings showing cerebral white matter demyelination (Loes score), very long chain fatty acid levels, ABCD1 gene mutation, adrenal function status, neurological examination findings, and consideration or status of stem cell transplantation.
- ✓Record rate of neurological progression.