2027 ICD-10-CM Diagnosis Code G43.409Hemiplegic migraine, not intractable, without status migrainosus
ICD-10-CM Codes›G00–G99›G40-G47›G43
- Billable — Valid for Submission
- Chronic Condition
G43.409 is a billable ICD-10-CM diagnosis code for hemiplegic migraine, not intractable, without status migrainosus. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 102 through 103. Coders also document this condition as familial hemiplegic migraine. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Headache; including migraine.
G43.409 does not risk-adjust for Medicare Advantage under the CMS-HCC V28 model. It still risk-adjusts in the RxHCC Part D (V08) category 166 for payment year 2027.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
G43.409 does not risk-adjust for Medicare Advantage under the CMS-HCC V28 model, but it maps to payment categories in the other CMS models shown below.
Source: CMS Payment Year 2027 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Familial hemiplegic migraine
- Familial hemiplegic migraine type 1
- Familial hemiplegic migraine type 2
- Familial hemiplegic migraine type 3
- Hemiplegic migraine
- Sporadic hemiplegic migraine
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to G43.409: its own notes plus those printed at G43 and Chapter 6. A note printed at a category, block or chapter applies to every code under it.
Applicable To
Conditions this code is used for: synonyms of the title or, for "other specified" codes, the conditions assigned to it. The list is not exhaustive.
- Hemiplegic migraine NOS
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
Excludes2
Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.
- certain conditions originating in the perinatal period (P04-P96)
- certain infectious and parasitic diseases (A00-B99)
- complications of pregnancy, childbirth and the puerperium (O00-O9A)
- congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
- endocrine, nutritional and metabolic diseases (E00-E88)
- injury, poisoning and certain other consequences of external causes (S00-T88)
- neoplasms (C00-D49)
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
Use Additional Code
Add a second code, after this one, to fully describe the condition.
Notes
General instructions on how these codes are used.
- the following terms are to be considered equivalent to intractable: pharmacoresistant (pharmacologically resistant), treatment resistant, refractory (medically) and poorly controlled
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name G43.409, its category, or a range that includes it.
Excludes2 4
These codes carry an Excludes2 note naming G43.409: its condition is not part of those codes, and both may be reported when the patient has both.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
hemiplegic G43.409
not intractable G43.409
without status migrainosus G43.409
without refractory migraine G43.409
without status migrainosus G43.409
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Migraine Disorders
a class of disabling primary headache disorders, characterized by recurrent unilateral pulsatile headaches. the two major subtypes are common migraine (without aura) and classic migraine (with aura or neurological symptoms). (international classification of headache disorders, 2nd ed. cephalalgia 2004: suppl 1)
Patient EducationClinical
Migraine
Migraines are a recurring type of headache. They cause moderate to severe pain that is throbbing or pulsing. The pain is often on one side of your head. You may also have other symptoms, such as nausea and weakness. You may be sensitive to light and sound.
The full article covers:
- What are migraines?
- What causes migraines?
- Who is at risk for migraines?
- What are the symptoms of migraines?
- How are migraines diagnosed?
- How are migraines treated?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert G43.409 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About G43.409Overview
What is the ICD-10 code for hemiplegic migraine, not intractable, without status migrainosus?
The ICD-10-CM code for hemiplegic migraine, not intractable, without status migrainosus is G43.409 (sometimes written as G43409). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is G43.409 (Hemiplegic migraine, not intractable) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report hemiplegic migraine, not intractable, without status migrainosus on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does G43.409 group to?
When hemiplegic migraine, not intractable, without status migrainosus is the principal diagnosis on an inpatient stay, it groups to MS-DRG 102, 103, with relative weights from 0.8219 to 1.1200 depending on complications. Higher weights mean higher Medicare reimbursement.
Can G43.409 be reported with G44.00?
Not as a rule. The Excludes1 note at G43, which applies to G43.409, lists "lower half migraine (G44.00)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).
Does G43.409 need an additional code?
When the condition applies, yes. The Use Additional Code note at G43, which applies to G43.409, reads: code for adverse effect, if applicable, to identify drug (T36-T50 with fifth or sixth character 5). The additional code is reported after G43.409.
Does G43.409 risk-adjust for Medicare Advantage payment?
Not for Medicare Advantage: G43.409 maps to no category in the CMS-HCC V28 model. It still risk-adjusts in the RxHCC Part D (V08) category 166 (Migraine Headaches).
