2027 ICD-10-CM Diagnosis Code G40.801Other epilepsy, not intractable, with status epilepticus

ICD-10-CM Codes›G00–G99›G40-G47›G40

ICD-10-CM G40.801
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

G40.801 is a billable ICD-10-CM diagnosis code for other epilepsy, not intractable, with status epilepticus. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 23, 100 through 101. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 89 closely related codes. Coders also document this condition as status epilepticus without prominent motor symptoms. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Epilepsy; convulsions.

For Medicare Advantage risk adjustment, G40.801 maps to CMS-HCC Category 201 (Seizure Disorders and Convulsions) under the V28 model, adding a risk factor of about 0.245 for a community, non-dual, aged beneficiary in payment year 2027.

Code Identity

ICD-10-CM Code
G40.801
Billable Status
Yes — Valid for Submission
Code Describes
Other epilepsy, not intractable, with status epilepticus
Short Description
Other epilepsy, not intractable, with status epilepticus
Same as the full description in the CMS dataset.
Parent Code
Other epilepsy

Code Classification

ChapterG00–G99Diseases of the nervous system
SectionG40-G47Episodic and paroxysmal disorders
CategoryG40Epilepsy and recurrent seizures
This CodeG40.801Other epilepsy, not intractable, with status epilepticus

Medicare Risk Adjustment (HCC)Billing

G40.801 maps to a payment category in the CMS-HCC model used to risk-adjust Medicare Advantage payments. Weights are the published community factors for payment year 2027.

CMS-HCC V28 Category (Payment Model)
HCC 201— Seizure Disorders and Convulsions
Payment HCC · PY 2027 one of 64 ICD-10-CM codes in this category
Risk Adjustment Factor (RAF) Weight
+0.245
community, non-dual, aged · ranges 0.131–0.245 across segments
Hierarchy
Top of its hierarchy
HCC 201 is not superseded by any other condition category
Prior Model (CMS-HCC V24)
HCC 79
V24 retired V28 pays 100% of MA risk scores since PY 2026
Other CMS Models
PACE (CMS-HCC V22): HCC 79 · ESRD (V21): HCC 79 · ESRD (V24): HCC 79
ESRD V21 weights: 0.066 dialysis, 0.065–0.221 functioning graft · ESRD V24 weights: 0.053 dialysis, 0.070–0.249 functioning graft
Part D (RxHCC)
RxHCC 164 — Epilepsy and Other Seizure Disorders, Except Intractable Epilepsy
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.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Status epilepticus without prominent motor symptoms

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to G40.801: its own notes plus those printed at G40 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.

  • Other epilepsy without intractability with status epilepticus

Excludes1

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

From G40 Epilepsy and recurrent seizures applies to 58 codes
  • conversion disorder with seizures (F44.5)
  • convulsions NOS (R56.9)
  • post traumatic seizures (R56.1)
  • seizure (convulsive) NOS (R56.9)
  • seizure of newborn (P90)

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 G40 Epilepsy and recurrent seizures applies to 58 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)

Notes

General instructions on how these codes are used.

From G40 Epilepsy and recurrent seizures applies to 58 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 G40.801, its category, or a range that includes it.

Excludes1 3

These codes carry an Excludes1 note naming G40.801: they are not reported together with it, unless the two conditions are unrelated.

  • G25.3 Myoclonus
    myoclonic epilepsy (G40.-) names G40.-, which includes this code
  • R56 Convulsions, not elsewhere classified
    epileptic convulsions and seizures (G40.-) names G40.-, which includes this code
  • R56.1 Post traumatic seizures
    post traumatic epilepsy (G40.-) names G40.-, which includes this code

Excludes2 4

These codes carry an Excludes2 note naming G40.801: its condition is not part of those codes, and both may be reported when the patient has both.

  • F44.0 Dissociative amnesia
    postictal amnesia in epilepsy (G40.-) names G40.-, which includes this code
  • F44.1 Dissociative fugue
    postictal fugue in epilepsy (G40.-) names G40.-, which includes this code
  • F80.1 Expressive language disorder
    acquired aphasia with epilepsy [Landau-Kleffner] (G40.80-) names G40.80-, which includes this code
  • F80.2 Mixed receptive-expressive language disorder
    acquired aphasia with epilepsy [Landau-Kleffner] (G40.80-) names G40.80-, which includes this code

Code First 1

These codes say to code first a condition named in the note, and G40.801 is one of the conditions named.

  • F02 Dementia in other diseases classified elsewhere
    epilepsy and recurrent seizures (G40.-) names G40.-, which includes this code

Use Additional Code 2

These codes say to use an additional code from the note, and G40.801 is one of the codes named.

  • Q87.87 Hao-Fountain Syndrome
    epilepsy, by specific type (G40.-) names G40.-, which includes this code
  • Q93.52 Phelan-McDermid syndrome
    epilepsy and recurrent seizures (G40.-) names G40.-, which includes this code

Code Also 10

These codes say G40.801 may also be needed to fully describe the condition. The note gives no sequencing direction.

  • E20.810 Autosomal dominant hypocalcemia
    seizure disorder (G40.-, R56.9) names G40.-, which includes this code
  • F78.A1 SYNGAP1-related intellectual disability
    epilepsy and recurrent seizures (G40.-) names G40.-, which includes this code
  • G04.8 Other encephalitis, myelitis and encephalomyelitis
    any associated seizure (G40.-, R56.9) names G40.-, which includes this code
  • G40.5 Epileptic seizures related to external causes
    if applicable, associated epilepsy and recurrent seizures (G40.-) names G40.-, which includes this code
  • G43.1 Migraine with aura
    any associated seizure (G40.-, R56.9) names G40.-, which includes this code
  • G93.45 Developmental and epileptic encephalopathy
    epilepsy, by specific type (G40.-) names G40.-, which includes this code
  • I67.850 Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy
    epilepsy (G40.-) names G40.-, which includes this code
  • Q87.85 MED13L syndrome
    epilepsy and recurrent seizures (G40.-) names G40.-, which includes this code
  • QA0 Neurodevelopmental disorders related to specific genetic pathogenic variants
    epilepsy, by specific type (G40.-) names G40.-, which includes this code
  • Z15.1 Genetic susceptibility to epilepsy and neurodevelopmental disorders
    epilepsy, by specific type (G40.-) names G40.-, which includes this code

Index to Diseases and InjuriesGuidance

Clinical ClassificationClinical

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

CCSR NVS009
Epilepsy; convulsions
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Epilepsy

Epilepsy is a brain disorder that causes people to have recurring seizures. The seizures happen when clusters of nerve cells, or neurons, in the brain send out the wrong signals. People may have strange sensations and emotions or behave strangely. They may have violent muscle spasms or lose consciousness.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert G40.801 to ICD-9-CMHistory

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

ICD-9-CM
345.80 Epilep NEC w/o intr epil
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 G40.801Overview

What is the ICD-10 code for other epilepsy, not intractable, with status epilepticus?

The ICD-10-CM code for other epilepsy, not intractable, with status epilepticus is G40.801 (sometimes written as G40801). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is G40.801 (Other epilepsy) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report other epilepsy, not intractable, with status epilepticus on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does G40.801 group to?

When other epilepsy, not intractable, with status epilepticus is the principal diagnosis on an inpatient stay, it groups to MS-DRG 100, 23, 101, with relative weights from 0.8952 to 5.7422 depending on complications. Higher weights mean higher Medicare reimbursement.

Is G40.801 a CC or MCC?

CMS lists G40.801 as a CC (complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 89 closely related codes in its exclusion list.

Can G40.801 be reported with F44.5?

Not as a rule. The Excludes1 note at G40, which applies to G40.801, lists "conversion disorder with seizures (F44.5)". 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).

What HCC is G40.801?

G40.801 (other epilepsy, not intractable, with status epilepticus) maps to CMS-HCC Category 201 (Seizure Disorders and Convulsions), commonly written as HCC 201, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2027. It mapped to HCC 79 under the retired V24 model. It also maps in the PACE (CMS-HCC V22), ESRD (V21), and ESRD (V24) models. In the Part D prescription drug model it maps to RxHCC 164.

Does G40.801 risk-adjust for Medicare Advantage payment?

Yes. When documented and reported on a Medicare Advantage encounter, G40.801 adds a risk adjustment factor of about 0.245 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.131 to 0.245 depending on the payment segment). HCC 201 sits at the top of its hierarchy, so no other condition category supersedes it. See the full factor table on the HCC 201 category page.