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

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for G93.45 in the official ICD-10-CM tabular list, quoted as published.

Source: CMS/CDC — ICD-10-CM Tabular ListRelease: FY2026Effective: October 1, 2025

Notes without a marker are published on G93.45 itself; “inherited from” names the category or block whose note applies here.

Coder workflow for G93.45

MedCoder structured workflow — derived from this code’s own official record

Documentation check

The provider’s diagnostic statement

Codes are assigned from the provider’s documented diagnosis, not from clinical criteria, test values or a medication list (Guidelines I.A.19).

The associated condition or complication

Whether the associated condition the title names is documented; the “with” convention presumes some links, and a provider statement that the conditions are unrelated defeats it (Guidelines I.A.15).

Official instructions as workflow

• Excludes2 — not part of G93.45(4 notes)

  Coding workflow: The conditions named in this note are not included in G93.45. When the record documents both, both may be reported; the note is a boundary, not a prohibition.

  CompareG31.2, G94, I67.4, G92.8

  See the official tabular notes · Guidelines I.A.12.b

• Code Also — related condition(7 notes)

  Coding workflow: Review the related condition when both are documented and the instruction applies. A Code Also note does not fix sequencing; the order follows the circumstances of the encounter.

  ReviewF81, F80, G40, F88, F84

  See the official tabular notes · Guidelines I.A.17

Every row is derived from this code’s own record — its title, tabular notes, 7th-character family and same-category siblings — with fixed MedCoder wording; nothing is inferred about a patient. The official notes and guideline text are in the sections each row links to, and they control.

Indexed Clinical Terms (2)

Official source data — entries quoted as published, in the Index’s own lookup phrasing

Clinical term phrases from the official ICD-10-CM Index to Diseases and Injuries that map to this code. These are alphabetic-index entries shown as the Index writes them — lookup phrasing, not necessarily the wording of a final diagnosis.

• Encephalopathy (acute), developmental and epileptic
• Encephalopathy (acute), early infantile epileptic

Don’t confuse G93.45 with…

MedCoder analysis — pairs from this code’s official notes, distinctions written by MedCoder

The codes most likely to be picked instead of G93.45 — named in its own official notes, or sharing its laterality or encounter family — with what separates them and which documentation moves the case. Each links to the full comparison.

• G93.40— Specificity relationship (Review)

  Overlapping diagnoses in the same category.

  Overlapping codes in the same category — the documentation decides which is the more specific fit.

  What moves you there: A record that documents no more than “Encephalopathy, unspecified” takes G93.40; specificity in the record moves it back here.

  Full comparison: G93.45 vs G93.40 →

• G31.2— Excludes2 relationship (Informational)

  Distinct conditions — both may be reported.

  A distinct condition — both may be reported when both are documented.

  What moves you there: Documentation of alcoholic encephalopathy adds G31.2; it is not part of this code and both may be reported when both are documented.

  Full comparison: G93.45 vs G31.2 →

• G94— Excludes2 relationship (Informational)

  Distinct conditions — both may be reported.

  A distinct condition — both may be reported when both are documented.

  What moves you there: Documentation of encephalopathy in diseases classified elsewhere adds G94; it is not part of this code and both may be reported when both are documented.

  Full comparison: G93.45 vs G94 →

• I67.4— Excludes2 relationship (Informational)

  Distinct conditions — both may be reported.

  A distinct condition — both may be reported when both are documented.

  What moves you there: Documentation of hypertensive encephalopathy adds I67.4; it is not part of this code and both may be reported when both are documented.

  Full comparison: G93.45 vs I67.4 →

• G92.8— Excludes2 relationship (Informational)

  Distinct conditions — both may be reported.

  A distinct condition — both may be reported when both are documented.

  What moves you there: Documentation of toxic (metabolic) encephalopathy adds G92.8; it is not part of this code and both may be reported when both are documented.

  Full comparison: G93.45 vs G92.8 →

Relationships are read from this code's own official notes, its laterality siblings and its encounter family; the wording of each distinction is MedCoder editorial, and the documentation named in each “what moves you there” line is the official note phrase or sibling title itself. Source: CMS ICD-10-CM tabular instructional notes; ICD-10-CM Official Guidelines, Section I.A.12.a.

Verify Before Coding

• CC as a secondary diagnosis (FY2026). Can raise the stay's MS-DRG severity tier.

From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim in Claim Check.

Relationships & Classification

MedCoder structured relationships — computed from published CMS and AHRQ datasets

Other codes that name G93.45 or its code family, from the CMS ICD-10-CM tabular instructional notes. Tabular-note edges are stored at the code family level that carries each note.

Referenced by 3 Code Also instructions across 3 chapters: F78.A1 — SYNGAP1-related intellectual disability (via G93.4.-), QA0 — Neurodevelopmental disorders related to specific genetic pathogenic variants, Z15.1 — Genetic susceptibility to epilepsy and neurodevelopmental disorders.

These codes suggest coding this condition alongside when both are present.

MS-DRG Grouper Relationships (FY2026)

Potential MS-DRG participation — not a DRG assignment.

FY2026 MS-DRG: CC — Complication or Comorbidity. Reported as a secondary diagnosis, this code raises the stay's MS-DRG severity tier — except when the principal diagnosis is one of 9 clinically related codes on its CMS exclusion list. Does not count toward severity when the stay groups to DRGs 974-976 (HIV with Major Related Condition).

Named in the grouper logic of 6 MS-DRGs: DRG 070 (MDC 01), DRG 071 (MDC 01), DRG 072 (MDC 01), DRG 974 (MDC 25), DRG 975 (MDC 25), DRG 976 (MDC 25).

From the CMS MS-DRG Definitions Manual (Appendices B and C). Actual DRG assignment depends on the complete claim.

Clinical classification (AHRQ CCSR):NVS009 — Epilepsy; convulsions (default); NVS006 — Other nervous system disorders (often hereditary or degenerative).

Clinical Classifications Software Refined (CCSR) for ICD-10-CM Diagnoses. Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality.

Related Codes

Same clinical process (MS-DRG)

Acts as CC — raises the severity of other admissions. CMS groups these diagnoses into one MS-DRG principal-diagnosis exclusion process — a CC/MCC on this list never raises severity when the principal diagnosis is also on it.

G21.0 — Malignant neuroleptic syndrome, G83.5 — Locked-in state, G93.40 — Encephalopathy, unspecified, G93.41 — Metabolic encephalopathy, G93.42 — Megalencephalic leukoencephalopathy with subcortical cysts, G93.43 — Leukoencephalopathy with calcifications and cysts, G93.44 — Adult-onset leukodystrophy with axonal spheroids, G93.49 — Other encephalopathy

Same CMS-HCC risk category (V28)

CMS maps these diagnoses to the same Hierarchical Condition Category (Seizure Disorders and Convulsions) for risk-adjusted payment.

G40.909 — Epilepsy, unspecified, not intractable, without status epilepticus, G40.911 — Epilepsy, unspecified, intractable, with status epilepticus, G40.919 — Epilepsy, unspecified, intractable, without status epilepticus, G40.A01 — Absence epileptic syndrome, not intractable, with status epilepticus, G40.A09 — Absence epileptic syndrome, not intractable, without status epilepticus, G40.A11 — Absence epileptic syndrome, intractable, with status epilepticus, G40.A19 — Absence epileptic syndrome, intractable, without status epilepticus, G40.B01 — Juvenile myoclonic epilepsy, not intractable, with status epilepticus, G40.B09 — Juvenile myoclonic epilepsy, not intractable, without status epilepticus, G40.B11 — Juvenile myoclonic epilepsy, intractable, with status epilepticus, G40.B19 — Juvenile myoclonic epilepsy, intractable, without status epilepticus, G40.C01 — Lafora progressive myoclonus epilepsy, not intractable, with status epilepticus, G40.C09 — Lafora progressive myoclonus epilepsy, not intractable, without status epilepticus, G40.C11 — Lafora progressive myoclonus epilepsy, intractable, with status epilepticus, G40.C19 — Lafora progressive myoclonus epilepsy, intractable, without status epilepticus, P90 — Convulsions of newborn, R56.00 — Simple febrile convulsions, R56.01 — Complex febrile convulsions, R56.1 — Post traumatic seizures, R56.9 — Unspecified convulsions, +43 more

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical categories (Epilepsy; convulsions, Other nervous system disorders (often hereditary or degenerative)).

G40.B19 — Juvenile myoclonic epilepsy, intractable, without status epilepticus, G40.C01 — Lafora progressive myoclonus epilepsy, not intractable, with status epilepticus, G40.C09 — Lafora progressive myoclonus epilepsy, not intractable, without status epilepticus, G40.C11 — Lafora progressive myoclonus epilepsy, intractable, with status epilepticus, G40.C19 — Lafora progressive myoclonus epilepsy, intractable, without status epilepticus, G90.01 — Carotid sinus syncope, G90.09 — Other idiopathic peripheral autonomic neuropathy, G90.1 — Familial dysautonomia [Riley-Day], G90.3 — Multi-system degeneration of the autonomic nervous system, G90.4 — Autonomic dysreflexia, G90.B — LMNB1-related autosomal dominant leukodystrophy, G93.42 — Megalencephalic leukoencephalopathy with subcortical cysts, G93.43 — Leukoencephalopathy with calcifications and cysts, G93.44 — Adult-onset leukodystrophy with axonal spheroids, G99.0 — Autonomic neuropathy in diseases classified elsewhere, G99.2 — Myelopathy in diseases classified elsewhere, R56.00 — Simple febrile convulsions, R56.01 — Complex febrile convulsions, R56.1 — Post traumatic seizures, R56.9 — Unspecified convulsions, +145 more

Same Index main term, other category

The ICD-10-CM Index to Diseases and Injuries files this code under the main term “Encephalopathy”; these codes share that main term but sit in a different category of the Tabular List.

G04.31 — Postinfectious acute necrotizing hemorrhagic encephalopathy (acute necrotizing hemorrhagic, postinfectious), G04.32 — Postimmunization acute necrotizing hemorrhagic encephalopathy (acute necrotizing hemorrhagic, postimmunization), G04.39 — Other acute necrotizing hemorrhagic encephalopathy (acute necrotizing hemorrhagic, specified NEC), G31.2 — Degeneration of nervous system due to alcohol (alcoholic), G31.82 — Leigh's disease (necrotizing, subacute), G32.89 — Other specified degenerative disorders of nervous system in diseases classified elsewhere (degenerative, in specified disease NEC), G37.0 — Diffuse sclerosis of central nervous system (centrolobar progressive), G37.1 — Central demyelination of corpus callosum (demyelinating callosal), G92.8 — Other toxic encephalopathy (due to, drugs), G92.9 — Unspecified toxic encephalopathy (toxic), I67.2 — Cerebral atherosclerosis (arteriosclerotic), I67.4 — Hypertensive encephalopathy (hypertensive), K76.82 — Hepatic encephalopathy (hepatic), P11.1 — Other specified brain damage due to birth injury (in, birth injury), P57.0 — Kernicterus due to isoimmunization (hyperbilirubinemic, newborn, due to isoimmunization), P57.9 — Kernicterus, unspecified (hyperbilirubinemic, newborn), P91.60 — Hypoxic ischemic encephalopathy [HIE], unspecified (hypoxic ischemic), P91.61 — Mild hypoxic ischemic encephalopathy [HIE] (hypoxic ischemic, mild), P91.62 — Moderate hypoxic ischemic encephalopathy [HIE] (hypoxic ischemic, moderate), P91.63 — Severe hypoxic ischemic encephalopathy [HIE] (hypoxic ischemic, severe), +17 more

Lab tests where this diagnosis supports Medicare coverage (NCD)

Medicare's National Coverage Determination (NCD) program lists this diagnosis as medical justification for these lab tests.

HIV Screening Test

Contextual Map

Every relationship of G93.45 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Run G93.45 with these 11 related codes in Claim Check

Hierarchy

• G00-G99 — Chapter 6: Diseases of the Nervous System (G00-G99) (G00-G99)[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026

Code Also (11)

• F70 — Mild intellectual disabilities[Code Also]: “intellectual disabilities (F70-F79)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• F71 — Moderate intellectual disabilities[Code Also]: “intellectual disabilities (F70-F79)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• F72 — Severe intellectual disabilities[Code Also]: “intellectual disabilities (F70-F79)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• F73 — Profound intellectual disabilities[Code Also]: “intellectual disabilities (F70-F79)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• F78 — Other intellectual disabilities[Code Also]: “intellectual disabilities (F70-F79)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• F79 — Unspecified intellectual disabilities[Code Also]: “intellectual disabilities (F70-F79)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• F80 — Specific developmental disorders of speech and language[Code Also]: “developmental disorder of speech and language (F80.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• F81 — Specific developmental disorders of scholastic skills[Code Also]: “developmental disorders of scholastic skills (F81.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• and 3 more

Referenced by Code Also instructions

• F78.A1 — SYNGAP1-related intellectual disability[Code Also](via G93.4.-): “encephalopathy (G93.4-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• QA0 — Neurodevelopmental disorders related to specific genetic pathogenic variants[Code Also]: “developmental and epileptic encephalopathy (G93.45)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• Z15.1 — Genetic susceptibility to epilepsy and neurodevelopmental disorders[Code Also]: “developmental and epileptic encephalopathy (G93.45)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Clinical classification (CCSR)

• NVS009 — Epilepsy; convulsions[CCSR]— AHRQ CCSR for ICD-10-CM Diagnoses (HCUP)
• NVS006 — Other nervous system disorders (often hereditary or degenerative)[CCSR]— AHRQ CCSR for ICD-10-CM Diagnoses (HCUP)

Risk adjustment (CMS-HCC)

• HCC 201 — Seizure Disorders and Convulsions [CMS-HCC]— CMS-HCC V28 · 2026

MS-DRG Grouper

• CC — Complication or Comorbidity [MS-DRG severity]: “As a secondary diagnosis this code can raise the stay's MS-DRG severity tier (CC). Not counted when the stay groups to DRGs 974-976 (HIV with Major Related Condition).”— CMS MS-DRG Definitions Manual (Appendix C) · FY2026
• DRG 070 — OTHER CEREBROVASCULAR DISORDERS WITH MCC[MS-DRG]: “OTHER CEREBROVASCULAR DISORDERS WITH MCC (MDC 01)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026
• DRG 071 — OTHER CEREBROVASCULAR DISORDERS WITH CC[MS-DRG]: “OTHER CEREBROVASCULAR DISORDERS WITH CC (MDC 01)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026
• DRG 072 — OTHER CEREBROVASCULAR DISORDERS WITHOUT CC/MCC[MS-DRG]: “OTHER CEREBROVASCULAR DISORDERS WITHOUT CC/MCC (MDC 01)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026
• DRG 974 — HIV WITH MAJOR RELATED CONDITION WITH MCC[MS-DRG]: “HIV WITH MAJOR RELATED CONDITION WITH MCC (MDC 25)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026
• DRG 975 — HIV WITH MAJOR RELATED CONDITION WITH CC[MS-DRG]: “HIV WITH MAJOR RELATED CONDITION WITH CC (MDC 25)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026
• DRG 976 — HIV WITH MAJOR RELATED CONDITION WITHOUT CC/MCC[MS-DRG]: “HIV WITH MAJOR RELATED CONDITION WITHOUT CC/MCC (MDC 25)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026

MDC crossing

• MDC 01 — Diseases and Disorders of the Nervous System[MDC crossing]: “Diseases and Disorders of the Nervous System — the grouper's crossing between diagnoses and procedures: a principal diagnosis sets the MDC, and same-MDC procedures move the stay to its surgical DRGs. 8,892 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2026
• MDC 25 — Human Immunodeficiency Virus Infections[MDC crossing]: “Human Immunodeficiency Virus Infections — the grouper's crossing between diagnoses and procedures: a principal diagnosis sets the MDC, and same-MDC procedures move the stay to its surgical DRGs.”— CMS MS-DRG Definitions Manual · FY2026

Index entries

• Encephalopathy (acute), developmental and epileptic[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
• Encephalopathy (acute), early infantile epileptic[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026

Nearest codes (23)

• G93 — Other disorders of brain[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• G93.0 — Cerebral cysts[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• G93.1 — Anoxic brain damage, not elsewhere classified[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• G93.2 — Benign intracranial hypertension[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• G93.3 — Postviral and related fatigue syndromes[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• G93.31 — Postviral fatigue syndrome[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• G93.32 — Myalgic encephalomyelitis/chronic fatigue syndrome[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• G93.39 — Other post infection and related fatigue syndromes[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• and 15 more

Change history

• FY2025 — Added to the code set[Change history]— CMS release files (code change ledger) · icd10cm-fy2025

Sources for this page

Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.

Code, title, tabular notes and index terms Official source data

CMS/CDC ICD-10-CM FY2026 tabular list, index and tables, effective October 1, 2025 Release, file and checksum · Publisher’s page

Claim edits Official source data

CMS Definitions of Medicare Code Edits — v43.1 (April 2026) Release, file and checksum · Publisher’s page

Inpatient payment groups Official source data

CMS MS-DRG Definitions Manual (incl. Appendix B diagnosis index, Appendix C CC/MCC list, Appendix E procedure index) and IPPS Final Rule tables — v43 Release, file and checksum · Publisher’s page

Risk adjustment Official source data

2026 Mid-Year Final ICD-10 Mappings + Model Software (cms.gov/files/zip/2026-midyear-final-icd-10-mappings.zip, 2026-midyear-final-model-software.zip) — CMS-HCC V28, PY2026 mid-year final release Release, file and checksum · Publisher’s page

Change history and date-of-service validity Official source data

CMS ICD-10-CM release addenda, ingested release by release into the change ledger Release, file and checksum · Publisher’s page

Comparisons, relationships and the contextual map MedCoder structured relationship

Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears

Summary and FAQ answers MedCoder explanation

Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.

Labels on this page: Official source data · MedCoder structured relationship · MedCoder explanation. How to read the labels · All data sources and release dates

Nearest Codes in This Family

Official ICD-10-CM classifications closest to G93.45 in its code family, with their registry titles.

• G93.40 — Encephalopathy, unspecified
• G93.41 — Metabolic encephalopathy
• G93.42 — Megalencephalic leukoencephalopathy with subcortical cysts
• G93.43 — Leukoencephalopathy with calcifications and cysts
• G93.44 — Adult-onset leukodystrophy with axonal spheroids
• G93.49 — Other encephalopathy
• G93.5 — Compression of brain
• G93.6 — Cerebral edema
• G93.7 — Reye's syndrome
• G93.8 — Other specified disorders of brain

View all codes in the G93 family