G43.809 ICD-10-CM Code: Other migraine, not intractable, without status migrainosus
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 / Diseases of the nervous system (G00-G99) / Episodic and paroxysmal disorders (G40-G47)
G43.809
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceOther migraine, not intractable, without status migrainosus
An unusual or atypical type of migraine that is manageable with treatment and the patient is not currently in a prolonged migraine attack.
Buddy Insight
Other migraine codes capture migraine subtypes that do not fit standard categories such as retinal migraine, vestibular migraine, or migraine variants not elsewhere classified.
CMS-HCC V28
N/A—
Not mapped
CMS-HCC V24
N/A—
Not mapped
ACA/HHS
N/A—
Not mapped
ESRD/PACE
N/A—
Not mapped
RXHCC
MappedHCC 166
RAF 0.100
Code Book Path
Inclusion Terms
Official- Other migraine, without refractory migraine
Excludes 2
OfficialICD-10-CM does not list Excludes 2 notes for G43.809 in this effective period.
Related Child Codes
Includes
OfficialICD-10-CM does not list Includes notes for G43.809 in this effective period.
Excludes 1
OfficialICD-10-CM does not list Excludes 1 notes for G43.809 in this effective period.
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for G43.809 in this effective period.
Use Additional
OfficialICD-10-CM does not list Use Additional Code instructions for G43.809 in this effective period.
Code Also
OfficialICD-10-CM does not list Code Also instructions for G43.809 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 G43.809 an HCC code?
G43.809 is not in the CMS-HCC V28 or V24 community payment model, but it does map to Migraine under the Part D RxHCC model.
- Code
- G43.809
- Description
- Other migraine, not intractable, without status migrainosus
- 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 G43.809 in the Code Book — tabular path, V28 RAF, and MEAT checklist →
MEAT Criteria for G43.809
For G43.809 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 G43.809 during that encounter, not just copy-forwarded from a problem list.
Coder workflow notes
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What This Code Means
G43.809 is the ICD-10-CM diagnosis code for other migraine, not intractable, without status migrainosus. An unusual or atypical type of migraine that is manageable with treatment and the patient is not currently in a prolonged migraine attack. G43.809 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).
G43.809 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.
This code does not map to a CMS-HCC V28 payment category. Capture depends on documentation that supports the diagnosis; verify the HCC assignment against the current CMS mapping for the applicable payment year. Coders reviewing G43.809 should check whether additional documentation would support a more specific child code in the same hierarchy that does map to a payment HCC, capturing the correct specificity is the highest-impact RAF improvement available within accurate coding.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for G43.809 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Document the specific features that make this migraine 'other' or atypical compared to standard migraine classifications.
- •The '09' suffix indicates no status migrainosus; confirm the current migraine episode is not continuous or prolonged.
Clinical Significance
Other migraine codes capture migraine subtypes that do not fit standard categories such as retinal migraine, vestibular migraine, or migraine variants not elsewhere classified. These codes are important for accurately representing atypical presentations that still carry significant clinical burden and treatment needs. Proper use prevents both overcoding of more specific subtypes and undercoding to unspecified migraine.
Documentation Requirements
- ✓Specific migraine variant type documented by provider (e.g., retinal, vestibular, basilar-type features)
- ✓Clinical features that distinguish this from standard migraine with or without aura
- ✓Reason the condition does not fit a more specific migraine code category
- ✓Treatment responsiveness noted (not intractable = responsive to standard therapy)
- ✓Episode duration documented
- ✓Neurological examination findings specific to the variant type
- ✓Diagnostic workup results supporting the specific migraine variant diagnosis
Commonly Confused Codes
- •G43.001-G43.019 (Migraine without aura): use when presentation is classic migraine without aura features
- •G43.101-G43.119 (Migraine with aura): use for typical visual/sensory aura presentations
- •G43.401-G43.419 (Hemiplegic migraine): has its own specific code; do not use 'other' for hemiplegic type
- •G43.901-G43.919 (Migraine, unspecified): use only when type is truly not specified; 'other' requires a documented variant type
- •H34.x (Retinal vascular occlusions): retinal migraine involves transient monocular vision loss, not permanent vascular occlusion