2027 ICD-10-CM Diagnosis Code G43.C0Periodic headache syndromes in child or adult, not intractable

ICD-10-CM Codes›G00–G99›G40-G47›G43

ICD-10-CM G43.C0
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

G43.C0 is a billable ICD-10-CM diagnosis code for periodic headache syndromes in child or adult, not intractable. 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. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Headache; including migraine.

G43.C0 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

ICD-10-CM Code
G43.C0
Billable Status
Yes — Valid for Submission
Code Describes
Periodic headache syndromes in child or adult, not intractable
Short Description
Periodic headache syndromes in chld/adlt, not intractable
Parent Code
Periodic headache syndromes in child or adult

Code Classification

ChapterG00–G99Diseases of the nervous system
SectionG40-G47Episodic and paroxysmal disorders
CategoryG43Migraine
This CodeG43.C0Periodic headache syndromes in child or adult, not intractable

Medicare Risk Adjustment (HCC)Billing

G43.C0 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.

CMS-HCC V28 (Medicare Advantage Payment Model)
Not mapped
no payment category in the model that pays 100% of MA risk scores
Prior Model (CMS-HCC V24)
Not mapped under V24
this diagnosis newly risk-adjusts under the V28 model
Part D (RxHCC)
RxHCC 166 — Migraine Headaches
also risk-adjusts in the Part D prescription drug model (V08)

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.

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to G43.C0: 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.

  • Periodic headache syndromes in child or adult, without refractory migraine

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

From G43 Migraine applies to 48 codes

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.

From G43 Migraine applies to 48 codes
From Chapter 6 (G00-G99) Diseases of the nervous system applies to 700 codes
  • 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.

From G43 Migraine applies to 48 codes
  • code for adverse effect, if applicable, to identify drug (T36-T50 with fifth or sixth character 5)

Notes

General instructions on how these codes are used.

From G43 Migraine applies to 48 codes
  • 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.C0, its category, or a range that includes it.

Excludes2 4

These codes carry an Excludes2 note naming G43.C0: its condition is not part of those codes, and both may be reported when the patient has both.

  • G44 Other headache syndromes
    migraines (G43.-) names G43.-, which includes this code
  • G44.1 Vascular headache, not elsewhere classified
    migraine (G43.-) names G43.-, which includes this code
  • G89 Pain, not elsewhere classified
    migraines (G43.-) names G43.-, which includes this code
  • R51 Headache
    migraine and other headache syndromes (G43-G44) names G43-G44, which includes this code

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR NVS010
Headache; including migraine
Default principal diagnosis: inpatient Yes · outpatient Yes

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.C0 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
346.20 Vrnt mgrn wo ntr mgr NEC
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About G43.C0Overview

What is the ICD-10 code for periodic headache syndromes in child or adult, not intractable?

The ICD-10-CM code for periodic headache syndromes in child or adult, not intractable is G43.C0 (sometimes written as G43C0). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is G43.C0 (Periodic headache syndromes in child or adult) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report periodic headache syndromes in child or adult, not intractable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does G43.C0 group to?

When periodic headache syndromes in child or adult, not intractable 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.C0 be reported with G44.00?

Not as a rule. The Excludes1 note at G43, which applies to G43.C0, 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.C0 need an additional code?

When the condition applies, yes. The Use Additional Code note at G43, which applies to G43.C0, 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.C0.

Does G43.C0 risk-adjust for Medicare Advantage payment?

Not for Medicare Advantage: G43.C0 maps to no category in the CMS-HCC V28 model. It still risk-adjusts in the RxHCC Part D (V08) category 166 (Migraine Headaches).