What is ICD-10 code G43.E09?

G43.E09 is the ICD-10-CM diagnosis code for Chronic migraine with aura, not intractable, without status migrainosus. It belongs to the ICD-10-CM chapter for diseases of the nervous system (g00-g99). G43.E09 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. G43.E09 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. G43.E09 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. G43.E09 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 G43.E09?

G43.E09 does not map to a payment HCC under either the CMS-HCC V28 risk adjustment model or the older V24 model. V28 reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition. Because neither model rewards G43.E09 with a risk adjustment factor, it contributes zero to a Medicare Advantage beneficiary's RAF score in either version. Coders should check whether provider documentation supports a more specific child code that does map to a payment HCC.

What should coders know when reporting G43.E09?

Verify that the patient meets the definition of chronic migraine (≥15 headache days per month for ≥3 months) before assigning this code Confirm the migraine is 'not intractable' (responsive to treatment) and 'without status migrainosus' (not in a prolonged attack lasting >72 hours) to ensure accurate code selection

G43.E09: Chronic migraine with aura, not

ICD-10-CM Code View

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Code lookupG43.E09Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Diseases of the nervous system (G00-G99) / Episodic and paroxysmal disorders (G40-G47)

G43.E09

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

Chronic migraine with aura, not intractable, without status migrainosus

This code describes a long-term migraine condition where the patient experiences warning signs (aura) before the headache begins, but the migraines are manageable with treatment and the patient is not currently in a prolonged migraine attack. Chronic migraines occur 15 or more days per month for at least 3 months.

Buddy Insight

Chronic migraine with aura represents headache occurring 15 or more days per month for >3 months, with migraine features on at least 8 days AND associated aura symptoms.

CMS-HCC V28

Not risk-adjusted for this model/period.

RAF 0

CMS-HCC V24

Not risk-adjusted for this model/period.

RAF 0

ACA/HHS

Not risk-adjusted for this model/period.

RAF 0

ESRD/PACE

Not risk-adjusted for this model/period.

RAF 0

RXHCC

Mapped

HCC 166

Migraine

RAF 0.0

Code Trumping

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Code Book Path

Official

G43.EChronic migraine with aura

G43.E0Chronic migraine with aura, not intractable

G43.E09Chronic migraine with aura, not intractable, without status migrainosus

Inclusion Terms

Official

Chronic migraine with aura NOS

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for G43.E09 in this effective period.

Related Child Codes

Official

G43.E01Chronic migraine with aura, not intractable, with status migrainosus

Includes

Official

ICD-10-CM does not list Includes notes for G43.E09 in this effective period.

Excludes 1

Official

ICD-10-CM does not list Excludes 1 notes for G43.E09 in this effective period.

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for G43.E09 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for G43.E09 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for G43.E09 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

Headache frequency >=15 days/month for >3 months documented

Migraine features present on at least 8 days per month

Aura symptoms documented: visual (scotoma, fortification spectra), sensory (paresthesias), or speech/language disturbance

Duration of chronic pattern exceeding 3 months

MEAT Support

HCC Buddy guidance

Headache frequency >=15 days/month for >3 months documented

Migraine features present on at least 8 days per month

Aura symptoms documented: visual (scotoma, fortification spectra), sensory (paresthesias), or speech/language disturbance

Duration of chronic pattern exceeding 3 months

Audit Caution

HCC Buddy guidance

Coding chronic migraine without aura (G43.7xx) when aura symptoms are documented — aura status changes the code

Using episodic migraine with aura codes when frequency clearly meets chronic criteria (>=15 days/month)

Not querying for aura status when chronic migraine is documented — the presence of aura affects both coding and clinical management

Confusing 'persistent aura' (prolonged single episode) with 'chronic with aura' (high frequency recurrence with aura)

Common Mistakes

HCC Buddy guidance

G43.701-G43.719 (Chronic migraine WITHOUT aura) — use when chronic pattern exists but no aura symptoms

G43.101-G43.119 (Migraine with aura, episodic) — use when aura is present but frequency is <15 days/month

G43.501-G43.519 (Persistent migraine aura without cerebral infarction) — different concept: persistent refers to prolonged single aura, not chronic frequency

G44.1 (Vascular headache, NEC) — less specific; code to chronic migraine with aura when documented

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 G43.E09 an HCC code?

No. G43.E09 is a billable ICD-10-CM code but does not map to any HCC category in V28, V24, ESRD, or RxHCC.

HCC Category Mapping

RxHCCHCC 166, Migraine

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 G43.E09

For G43.E09to 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 G43.E09 during that encounter, not just copy-forwarded from a problem list.

What This Code Means

G43.E09 is the ICD-10-CM diagnosis code for chronic migraine with aura, not intractable, without status migrainosus. This code describes a long-term migraine condition where the patient experiences warning signs (aura) before the headache begins, but the migraines are manageable with treatment and the patient is not currently in a prolonged migraine attack. Chronic migraines occur 15 or more days per month for at least 3 months. G43.E09 sits in the ICD-10-CM chapter for diseases of the nervous system (g00-g99), within the section covering episodic and paroxysmal disorders (g40-g47).

G43.E09 is a billable ICD-10-CM code but does not map to a payment HCC under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can be reported on Medicare Advantage encounter data submissions but it does not contribute to a beneficiary's RAF score and therefore does not affect risk-adjusted payments to the plan.

Maps to RxHCC 166 (Severe Head Injury) with a RAF weight of 0.000 in the prescription drug model. No mapping to CMS-HCC V28 or V24 payment models. The RxHCC mapping captures the significant pharmacy costs associated with chronic migraine (CGRP inhibitors, botulinum toxin, multiple preventive agents). No hierarchies apply.

HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for G43.E09 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Verify that the patient meets the definition of chronic migraine (≥15 headache days per month for ≥3 months) before assigning this code
•Confirm the migraine is 'not intractable' (responsive to treatment) and 'without status migrainosus' (not in a prolonged attack lasting >72 hours) to ensure accurate code selection

Clinical Significance

Chronic migraine with aura represents headache occurring 15 or more days per month for >3 months, with migraine features on at least 8 days AND associated aura symptoms. The combination of chronicity and aura is clinically significant because aura with high-frequency migraine increases cerebrovascular risk and affects contraceptive choices in women. Accurate coding captures both the chronic pattern and aura presence, which influences treatment decisions including avoidance of estrogen-containing contraceptives.

Documentation Requirements

✓Headache frequency >=15 days/month for >3 months documented
✓Migraine features present on at least 8 days per month
✓Aura symptoms documented: visual (scotoma, fortification spectra), sensory (paresthesias), or speech/language disturbance
✓Duration of chronic pattern exceeding 3 months
✓Treatment responsiveness documented (not intractable)
✓Individual attack duration documented
✓Headache diary or frequency log supporting chronic designation
✓Vascular risk assessment given aura presence (especially in women of reproductive age)

Commonly Confused Codes

•G43.701-G43.719 (Chronic migraine WITHOUT aura): use when chronic pattern exists but no aura symptoms
•G43.101-G43.119 (Migraine with aura, episodic): use when aura is present but frequency is <15 days/month
•G43.501-G43.519 (Persistent migraine aura without cerebral infarction): different concept: persistent refers to prolonged single aura, not chronic frequency
•G44.1 (Vascular headache, NEC): less specific; code to chronic migraine with aura when documented
•G43.901-G43.919 (Migraine, unspecified): loses both the chronic pattern and aura information

Child Codes

G43.E01Chronic migraine with aura, not intractable, with status migrainosus

G43.E09Chronic migraine with aura, not intractable, without status migrainosus

Code Hierarchy

└G43Migraine └G43.EChronic migraine with aura └G43.E0Chronic migraine with aura, not intractable └G43.E09Chronic migraine with aura, not intractable, without status migrainosus

└G43.E09Chronic migraine with aura, not intractable, without status migrainosus

G43.E09 ICD-10-CM Code: Chronic migraine with aura, not intractable, without status migrainosus

HCC Buddy Code Card

G43.E09

Is G43.E09 an HCC code?

HCC Category Mapping

MEAT Criteria for G43.E09

What This Code Means

Coding Tips

Clinical Significance

Documentation Requirements

Commonly Confused Codes

Child Codes

Code Hierarchy

Work G43.E09 in HCC Buddy