2027 ICD-10-CM Diagnosis Code G93.45Developmental and epileptic encephalopathy

ICD-10-CM Codes›G00–G99›G89-G99›G93

ICD-10-CM G93.45
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

G93.45 is a billable ICD-10-CM diagnosis code for developmental and epileptic encephalopathy. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 70 through 72, 974 through 976. 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 9 closely related codes. Coders also document this condition as developmental and epileptic encephalopathy with spike-and-wave activation in sleep. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Epilepsy; convulsions and Other nervous system disorders (often hereditary or degenerative).

For Medicare Advantage risk adjustment, G93.45 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
G93.45
Billable Status
Yes — Valid for Submission
Code Describes
Developmental and epileptic encephalopathy
Short Description
Developmental and epileptic encephalopathy
Same as the full description in the CMS dataset.
Parent Code
G93.4
Other and unspecified encephalopathy

Code Classification

ChapterG00–G99Diseases of the nervous system
SectionG89-G99Other disorders of the nervous system
CategoryG93Other disorders of brain
This CodeG93.45Developmental and epileptic encephalopathy

Medicare Risk Adjustment (HCC)Billing

G93.45 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HCC 201 is not superseded by any other condition category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.

  • Developmental and epileptic encephalopathy with spike-and-wave activation in sleep
  • Early-infantile developmental and epileptic encephalopathy
  • Epileptic encephalopathy
  • Epileptic encephalopathy with spike-and-wave activation in sleep

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to G93.45: its own notes plus those printed at G93.4 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.

  • Early infantile epileptic encephalopathy

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 G93.4 Other and unspecified encephalopathy applies to 7 codes
  • alcoholic encephalopathy (G31.2)
  • encephalopathy in diseases classified elsewhere (G94)
  • hypertensive encephalopathy (I67.4)
  • toxic (metabolic) encephalopathy (G92.8)
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)

Code Also

A second code may be needed to fully describe the condition; the note gives no sequencing direction.

  • if applicable, associated disorders such as:
  • developmental disorders of scholastic skills (F81.-)
  • developmental disorder of speech and language (F80.-)
  • epilepsy, by specific type (G40.-)
  • intellectual disabilities (F70-F79)
  • other neurodevelopmental disorder (F88)
  • pervasive developmental disorders (F84.-)

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name G93.45, its category, or a range that includes it.

Code Also 3

These codes say G93.45 may also be needed to fully describe the condition. The note gives no sequencing direction.

  • QA0 Neurodevelopmental disorders related to specific genetic pathogenic variants
    developmental and epileptic encephalopathy (G93.45)
  • Z15.1 Genetic susceptibility to epilepsy and neurodevelopmental disorders
    developmental and epileptic encephalopathy (G93.45)
  • F78.A1 SYNGAP1-related intellectual disability
    encephalopathy (G93.4-) names G93.4-, 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 NVS009
Epilepsy; convulsions
Default principal diagnosis: inpatient Yes · outpatient Yes
CCSR NVS006
Other nervous system disorders (often hereditary or degenerative)
Default principal diagnosis: inpatient No · outpatient No

Clinical InformationClinical

  • Developmental and Epileptic Encephalopathy

    a neurological disorder characterized by recurring seizures presenting within the first three months of life and progressive cerebral dysfunction.

Patient EducationClinical

Developmental Disabilities

Developmental disabilities are conditions that are usually present at birth. They can affect a child's growth and development. These conditions can cause physical, learning, language, or behavior issues. They can include:

The full article covers:

  • What are developmental disabilities?
  • What causes developmental disabilities?
  • How are developmental disabilities diagnosed?
  • What are the treatments for developmental disabilities?

Read the full article at MedlinePlus

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

Code History & ChangesHistory

Replacement G93.45 replaces the following previously assigned code(s):

  • G93.49 - Other encephalopathy
FY 2025AddedAdded to the ICD-10-CM code setEffective October 1, 2024.
FY 2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About G93.45Overview

What is the ICD-10 code for developmental and epileptic encephalopathy?

The ICD-10-CM code for developmental and epileptic encephalopathy is G93.45 (sometimes written as G9345). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is G93.45 (Other and unspecified encephalopathy) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report developmental and epileptic encephalopathy on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does G93.45 group to?

When developmental and epileptic encephalopathy is the principal diagnosis on an inpatient stay, it groups to MS-DRG 974, 976, 72, 975, 70, 71, with relative weights from 0.7344 to 3.0488 depending on complications. Higher weights mean higher Medicare reimbursement.

Is G93.45 a CC or MCC?

CMS lists G93.45 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 9 closely related codes in its exclusion list.

What HCC is G93.45?

G93.45 (developmental and epileptic encephalopathy) 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 G93.45 risk-adjust for Medicare Advantage payment?

Yes. When documented and reported on a Medicare Advantage encounter, G93.45 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.