What is ICD-10 code E74.810?

E74.810 is the ICD-10-CM diagnosis code for Glucose transporter protein type 1 deficiency. It belongs to the ICD-10-CM chapter for endocrine, nutritional and metabolic diseases (e00-e89). E74.810 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. E74.810 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. E74.810 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. E74.810 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 E74.810?

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. E74.810 was a payment HCC under V24 (Other Significant Endocrine and Metabolic Disorders) but the V28 recalibration removed it from the risk adjustment model. Both models can still appear in legacy data and in payer-specific lookback periods.

What should coders know when reporting E74.810?

This is a specific metabolic disorder code that requires documentation of the glucose transporter protein type 1 deficiency diagnosis; do not use more general glucose metabolism codes This condition is often associated with seizures and neurological symptoms, so review documentation for additional codes related to epilepsy or neurological manifestations that should be coded separately Because E74.810 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.

E74.810: Glucose transporter protein type 1 deficiency — ICD-10 | Other Significant Endocrine

ICD-10-CM Code View

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Code lookupE74.810Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Endocrine, nutritional and metabolic diseases (E00-E89) / Metabolic disorders (E70-E88)

E74.810

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

Glucose transporter protein type 1 deficiency

This is a rare genetic disorder where the body cannot properly transport glucose (sugar) into the brain due to a defective protein. This causes low blood sugar levels in the brain, leading to seizures, developmental delays, and movement problems.

Buddy Insight

Glucose transporter protein type 1 (GLUT1) deficiency syndrome is a genetic neurometabolic disorder where impaired glucose transport across the blood-brain barrier results in cerebral energy failure.

CMS-HCC V28

Not risk-adjusted for this model/period.

RAF 0

CMS-HCC V24

Mapped

HCC 23

Other Significant Endocrine a...

RAF 0.194

ACA/HHS

Not risk-adjusted for this model/period.

RAF 0

ESRD/PACE

Mapped

HCC 23

Other Significant Endocrine a...

RAF 0.0

RXHCC

Mapped

HCC 43

Other Significant Endocrine a...

RAF 0.0

Code Trumping

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Code Book Path

Official

E74.8Other specified disorders of carbohydrate metabolism

E74.81Disorders of glucose transport, not elsewhere classified

E74.810Glucose transporter protein type 1 deficiency

Inclusion Terms

Official

De Vivo syndrome
Glucose transport defect, blood-brain barrier
Glut1 deficiency
GLUT1 deficiency syndrome 1, infantile onset
GLUT1 deficiency syndrome 2, childhood onset

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for E74.810 in this effective period.

Related Child Codes

Official

E74.818Other disorders of glucose transport

E74.819Disorders of glucose transport, unspecified

Includes

Official

ICD-10-CM does not list Includes notes for E74.810 in this effective period.

Excludes 1

Official

ICD-10-CM does not list Excludes 1 notes for E74.810 in this effective period.

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for E74.810 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for E74.810 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for E74.810 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

Confirmed diagnosis of GLUT1 deficiency syndrome

Low cerebrospinal fluid glucose with normal blood glucose (hypoglycorrhachia)

SLC2A1 gene mutation analysis results

Documentation of seizure type and frequency

MEAT Support

HCC Buddy guidance

Confirmed diagnosis of GLUT1 deficiency syndrome

Low cerebrospinal fluid glucose with normal blood glucose (hypoglycorrhachia)

SLC2A1 gene mutation analysis results

Documentation of seizure type and frequency

Audit Caution

HCC Buddy guidance

Coding only the epilepsy without identifying the underlying GLUT1 deficiency

Confusing GLUT1 deficiency with systemic hypoglycemia — blood glucose is normal; only CSF glucose is low

Using a general glucose transport code when the specific GLUT1 code exists

Missing the diagnosis because the seizures respond partially to antiepileptic drugs and the metabolic cause is not investigated

Common Mistakes

HCC Buddy guidance

E74.818 — Other disorders of glucose transport: for glucose transport disorders other than GLUT1

E74.819 — Disorders of glucose transport, unspecified: use only when specific transport disorder is not identified

G40.89 — Other seizures: seizures are a manifestation of GLUT1 deficiency

E16.2 — Hypoglycemia, unspecified: blood glucose is normal in GLUT1 deficiency; the low glucose is in CSF only

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 E74.810 an HCC code?

Yes. E74.810 maps to Other Significant Endocrine and Metabolic Disorders under the V24 model but is not retained in V28.

HCC Category Mapping

V24HCC 23, Other Significant Endocrine and Metabolic Disorders

0.194

ESRDHCC 23, Other Significant Endocrine and Metabolic Disorders

0.000

RxHCCHCC 43, Other Significant Endocrine and Metabolic Disorders

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.

Work E74.810 in the Code Book — tabular path, V28 RAF, and MEAT checklist →

MEAT Criteria for E74.810

For E74.810to 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 E74.810 during that encounter, not just copy-forwarded from a problem list.

Coder workflow notes

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What This Code Means

E74.810 is the ICD-10-CM diagnosis code for glucose transporter protein type 1 deficiency. This is a rare genetic disorder where the body cannot properly transport glucose (sugar) into the brain due to a defective protein. This causes low blood sugar levels in the brain, leading to seizures, developmental delays, and movement problems. E74.810 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, E74.810 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.

This is a specific metabolic disorder code that requires documentation of the glucose transporter protein type 1 deficiency diagnosis; do not use more general glucose metabolism codes. Because E74.810 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 E74.810 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•This is a specific metabolic disorder code that requires documentation of the glucose transporter protein type 1 deficiency diagnosis; do not use more general glucose metabolism codes
•This condition is often associated with seizures and neurological symptoms, so review documentation for additional codes related to epilepsy or neurological manifestations that should be coded separately

Clinical Significance

Glucose transporter protein type 1 (GLUT1) deficiency syndrome is a genetic neurometabolic disorder where impaired glucose transport across the blood-brain barrier results in cerebral energy failure. Patients develop epilepsy (often drug-resistant), developmental delay, acquired microcephaly, and complex movement disorders. The ketogenic diet is the primary treatment, providing ketone bodies as an alternative brain fuel source.

Documentation Requirements

✓Confirmed diagnosis of GLUT1 deficiency syndrome
✓Low cerebrospinal fluid glucose with normal blood glucose (hypoglycorrhachia)
✓SLC2A1 gene mutation analysis results
✓Documentation of seizure type and frequency
✓Ketogenic diet implementation and adherence status
✓Neurological assessment including developmental milestones and movement disorder evaluation

Commonly Confused Codes

•E74.818: Other disorders of glucose transport: for glucose transport disorders other than GLUT1
•E74.819: Disorders of glucose transport, unspecified: use only when specific transport disorder is not identified
•G40.89: Other seizures: seizures are a manifestation of GLUT1 deficiency
•E16.2: Hypoglycemia, unspecified: blood glucose is normal in GLUT1 deficiency; the low glucose is in CSF only
•E74.9: Disorder of carbohydrate metabolism, unspecified: much less specific