E72.81 ICD-10-CM Code: Disorders of gamma aminobutyric acid metabolism
HCC Buddy Code Card
Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.
FY 2026 Apr update / Endocrine, nutritional and metabolic diseases (E00-E89) / Metabolic disorders (E70-E88)
E72.81
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceDisorders of gamma aminobutyric acid metabolism
A rare metabolic disorder affecting the body's ability to produce or use GABA, a neurotransmitter important for calming nerve activity in the brain.
Buddy Insight
Disorders of gamma-aminobutyric acid (GABA) metabolism are rare neurometabolic conditions that disrupt the brain's primary inhibitory neurotransmitter system.
CMS-HCC V28
N/A—
Not mapped
CMS-HCC V24
MappedHCC 23
RAF 0.194
ACA/HHS
MappedHCC 28
Varies by metal level
ESRD/PACE
MappedHCC 23
RAF 0.036
RXHCC
MappedHCC 43
RAF 0.063
Code Book Path
Inclusion Terms
Official- 4-hydroxybutyric aciduria
- Disorders of GABA metabolism
- GABA metabolic defect
- GABA transaminase deficiency
- GABA-T deficiency
Excludes 2
OfficialICD-10-CM does not list Excludes 2 notes for E72.81 in this effective period.
Related Child Codes
Includes
OfficialICD-10-CM does not list Includes notes for E72.81 in this effective period.
Excludes 1
OfficialICD-10-CM does not list Excludes 1 notes for E72.81 in this effective period.
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for E72.81 in this effective period.
Use Additional
OfficialICD-10-CM does not list Use Additional Code instructions for E72.81 in this effective period.
Code Also
OfficialICD-10-CM does not list Code Also instructions for E72.81 in this effective period.
Buddy Documentation Tip
MEAT Support
Audit Caution
Common Mistakes
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 E72.81 an HCC code?
Yes. E72.81 maps to Other Significant Endocrine and Metabolic Disorders under the V24 model but is not retained in V28.
- Code
- E72.81
- Description
- Disorders of gamma aminobutyric acid metabolism
- HCC (V28)
- No CMS-HCC V28 mapping
- RAF
- —
- Billable
- Yes
- Payment year
- 2026
HCC Category Mapping
Each model's RAF is its CMS base weight for that model's standard population, so 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 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.
Work E72.81 in the Code Book — tabular path, V28 RAF, and MEAT checklist →
MEAT Criteria for E72.81
For E72.81 to 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 E72.81 during that encounter, not just copy-forwarded from a problem list.
Coder workflow notes
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What This Code Means
E72.81 is the ICD-10-CM diagnosis code for disorders of gamma aminobutyric acid metabolism. A rare metabolic disorder affecting the body's ability to produce or use GABA, a neurotransmitter important for calming nerve activity in the brain. E72.81 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, E72.81 maps to Other Significant Endocrine and Metabolic Disorders (HCC 23) with a community, non-dual, aged base RAF weight of 0.194. 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.
Document any neurological symptoms such as seizures, developmental delay, or movement disorders. Because E72.81 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 E72.81 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Document any neurological symptoms such as seizures, developmental delay, or movement disorders
- •Note whether this is a deficiency or excess of GABA metabolism
Clinical Significance
Disorders of gamma-aminobutyric acid (GABA) metabolism are rare neurometabolic conditions that disrupt the brain's primary inhibitory neurotransmitter system. These include succinic semialdehyde dehydrogenase deficiency and GABA-transaminase deficiency, causing seizures, developmental delay, and movement disorders. These patients require specialized neurological care and metabolic management, making accurate coding critical for risk adjustment.
Documentation Requirements
- ✓Specific GABA metabolism disorder identified (e.g., succinic semialdehyde dehydrogenase deficiency, GABA-transaminase deficiency)
- ✓Laboratory confirmation such as elevated 4-hydroxybutyric acid in urine or abnormal GABA levels in cerebrospinal fluid
- ✓Genetic testing results if available
- ✓Documentation of neurological manifestations including seizures, ataxia, or behavioral disturbances
- ✓Current treatment plan and medications for symptom management
Commonly Confused Codes
- •E72.89: Other specified disorders of amino-acid metabolism: broader category; GABA disorders have their own specific code
- •G40.89: Other seizures: seizures are a symptom of GABA disorders, not the primary diagnosis
- •E72.9: Disorder of amino-acid metabolism, unspecified: non-specific; avoid when GABA disorder is documented
- •F88: Other disorders of psychological development: developmental delay is a manifestation, not the underlying cause