What is ICD-10 code G43.811?

G43.811 is the ICD-10-CM diagnosis code for Other migraine, intractable, with status migrainosus. It belongs to the ICD-10-CM chapter for diseases of the nervous system (g00-g99). G43.811 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. G43.811 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. G43.811 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. G43.811 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 G43.811?

G43.811 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 G43.811 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 G43.811?

Verify that the migraine is documented as 'intractable' (resistant to treatment) and that status migrainosus is explicitly mentioned in the clinical notes before assigning this code This code requires documentation of failed treatment attempts; ensure the provider has documented why standard migraine treatments were ineffective

G43.811: Other migraine, intractable, with status migrainosus — ICD-10

ICD-10-CM Code View

HCC Buddy Code Card

Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.

Code lookupG43.811Effective periodFY2026 Apr Update (Apr 1-Sep 30)

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

G43.811

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

Other migraine, intractable, with status migrainosus

This code describes a severe migraine headache that doesn't respond well to treatment and is accompanied by status migrainosus, which is a prolonged migraine attack lasting more than 72 hours. The migraine doesn't fit into other specific migraine categories.

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

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

Basket needed

Compare selected patient codes to show trumped or trumps impact.

Code Book Path

Official

G43.8Other migraine

G43.81Other migraine, intractable

G43.811Other migraine, intractable, with status migrainosus

Inclusion Terms

Official

Other migraine, with refractory migraine

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for G43.811 in this effective period.

Related Child Codes

Official

G43.819Other migraine, intractable, without status migrainosus

Includes

Official

ICD-10-CM does not list Includes notes for G43.811 in this effective period.

Excludes 1

Official

ICD-10-CM does not list Excludes 1 notes for G43.811 in this effective period.

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for G43.811 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for G43.811 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for G43.811 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

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

Intractability status documented

MEAT Support

HCC Buddy guidance

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

Intractability status documented

Audit Caution

HCC Buddy guidance

Using 'other migraine' as a catch-all when a more specific code exists — always check for hemiplegic, chronic, persistent aura codes first

Coding 'other' when the type is simply unspecified — 'other' means the provider named a specific variant that lacks its own code

Not documenting the specific migraine variant that justifies the 'other' category

Confusing retinal migraine (monocular, reversible) with retinal vascular disease

Common Mistakes

HCC Buddy guidance

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

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 G43.811 an HCC code?

No. G43.811 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 G43.811

For G43.811to 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 G43.811 during that encounter, not just copy-forwarded from a problem list.

Coder workflow notes

Get the V28 RAF + MEAT cheat sheet

One printable page: confirm a code's V28 HCC status, its RAF weight, and the MEAT your note needs to make it stick. Free, no card.

Free PDF. No card. Unsubscribe anytime.

What This Code Means

G43.811 is the ICD-10-CM diagnosis code for other migraine, intractable, with status migrainosus. This code describes a severe migraine headache that doesn't respond well to treatment and is accompanied by status migrainosus, which is a prolonged migraine attack lasting more than 72 hours. The migraine doesn't fit into other specific migraine categories. G43.811 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).

G43.811 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. This code influences pharmacy risk prediction only. No hierarchies apply. Consider whether a more specific migraine code might capture additional risk adjustment value.

HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for G43.811 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Verify that the migraine is documented as 'intractable' (resistant to treatment) and that status migrainosus is explicitly mentioned in the clinical notes before assigning this code
•This code requires documentation of failed treatment attempts; ensure the provider has documented why standard migraine treatments were ineffective

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
✓Intractability status documented
✓Status migrainosus with duration >72 hours if applicable
✓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

Child Codes

G43.811Other migraine, intractable, with status migrainosus

G43.819Other migraine, intractable, without status migrainosus

Code Hierarchy

└G43Migraine └G43.8Other migraine └G43.81Other migraine, intractable └G43.811Other migraine, intractable, with status migrainosus

└G43.811Other migraine, intractable, with status migrainosus

G43.811 ICD-10-CM Code: Other migraine, intractable, with status migrainosus

HCC Buddy Code Card

G43.811

Is G43.811 an HCC code?

HCC Category Mapping

MEAT Criteria for G43.811

Get the V28 RAF + MEAT cheat sheet

What This Code Means

Coding Tips

Clinical Significance

Documentation Requirements

Commonly Confused Codes

Child Codes

Code Hierarchy

Work G43.811 in HCC Buddy