R40.2434 ICD-10-CM Code: Glasgow coma scale score 3-8, 24 hours or more after hospital admission

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for R40.2434 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 R40.2434 itself; “inherited from” names the category or block whose note applies here.

7th Character Guide

"The following appropriate 7th character is to be added to subcategory R40.24-:"

• 0 — unspecified time
• 1 — in the field [EMT or ambulance]
• 2 — at arrival to emergency department
• 3 — at hospital admission
• 4 — 24 hours or more after hospital admission (this page’s code)

Variant codes in this family

R40.2430, R40.2431, R40.2432, R40.2433, R40.2434

Character meanings are CMS's official 7th-character extensions for this family, as carried in each variant code's official description; variant codes are registry rows. The explanation of how the encounter character is assigned is MedCoder editorial, distinct from the official content above it.

Coder workflow for R40.2434

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

Before you code R40.2434

1. Check whether an established diagnosis that explains this sign or symptom is documented. If one is, review whether the documented diagnosis changes the coding pathway: a symptom that is integral to a confirmed diagnosis is not reported separately, while one not routinely associated with it may be. Signs and symptoms are reported when no definitive diagnosis is established (Guidelines I.B.4, I.B.5, I.B.6, I.C.18.b).

   Guide: Symptom code vs confirmed diagnosis →

2. A 7th character is required in this family. Confirm the documentation supports the character assigned — its meaning in this family is defined in the official instruction. This page’s code carries “4”. The official 7th-character definitions for this family are quoted in the guide.

   See the 7th Character Guide

3. Check the Excludes1 note: if the documentation supports a condition named there, do not simply proceed with R40.2434. Excludes1 conditions are not reported together with this code unless the record shows they are unrelated (Guidelines I.A.12.a).

   See the official tabular notes

Choose the right path

1. Is an established diagnosis that explains this sign or symptom documented?
   Yes → Review whether the documented diagnosis changes the coding pathway: a symptom integral to it is not reported separately.
   No → Continue — the sign or symptom code stands when no definitive diagnosis is established.
2. Does the documentation support a condition named in R40.2434’s Excludes1 note?
   Yes → Do not simply proceed: review the excluded code. Both are reported only when the record shows the two conditions are unrelated.
   No → Continue.

   ReviewP91.5, K72, E15

3. Is the underlying (etiologic) condition the Code First note names documented?
   Yes → Sequence the underlying condition first, then R40.2434.
   No → Continue; do not add an underlying condition the record does not document.

   ReviewS02, S06

4. Does the documentation support one of this family’s 7th-character values?
   Yes → Assign the matching 7th character; the variant codes are in the 7th Character Guide.
   No → The code is invalid without its 7th character — query for the missing element.

Consider R40.2434. Then confirm the code is valid for the date of service in the Verify section.

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).

7th-character basis

The documented element this family’s 7th character records (see the official definitions in the 7th Character Guide).

The underlying (etiologic) condition

Named in the Code First note; sequenced before this code when documented (Guidelines I.A.13).

Official instructions as workflow

• Excludes1 — check before selecting R40.2434(4 notes)

  Coding workflow: If the documentation supports a condition named in this note, do not simply proceed with R40.2434: the two are not reported together. The one exception is when the record shows the two conditions are unrelated to each other.

  CompareP91.5, K72, E15

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

• Excludes2 — not part of R40.2434(1 note)

  Coding workflow: The conditions named in this note are not included in R40.2434. When the record documents both, both may be reported; the note is a boundary, not a prohibition.

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

• Code First — sequencing check(3 notes)

  Coding workflow: Check whether the underlying or etiologic condition the note names is documented. When it is, sequence it before R40.2434. Do not add an underlying condition the record does not document.

  ReviewS02, S06

  See the official tabular notes · Guidelines I.A.13

Coding decision scenarios

Pattern scenarios for this code’s structure — decision rules, not clinical cases

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.

Official Coding Guidelines

Official source data — quoted verbatim from the CMS/NCHS Official Guidelines

Official source data — quoted verbatim from the CMS/NCHS Official Guidelines

Verbatim excerpts from the ICD-10-CM Official Guidelines for Coding and Reporting (CMS/NCHS) that govern this code.

Don’t confuse R40.2434 with…

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

The codes most likely to be picked instead of R40.2434 — 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.

• P91.5— Excludes1 conflict (Excludes1 — generally not reported together)

  Not coded here — the tabular list excludes this pair for the same encounter.

  Not reported together with this code, except where the two conditions are documented as unrelated.

  What moves you there: Documentation of neonatal coma moves the case to P91.5; the two are not reported together unless documented as unrelated.

  Full comparison: R40.2434 vs P91.5 →

• E08— Excludes1 conflict (Excludes1 — generally not reported together)

  Not coded here — the tabular list excludes this pair for the same encounter.

  Not reported together with this code, except where the two conditions are documented as unrelated.

  What moves you there: Documentation of somnolence, stupor and coma in diabetes moves the case to E08; the two are not reported together unless documented as unrelated.

  Full comparison: R40.2434 vs E08 →

• E13— Excludes1 conflict (Excludes1 — generally not reported together)

  Not coded here — the tabular list excludes this pair for the same encounter.

  Not reported together with this code, except where the two conditions are documented as unrelated.

  What moves you there: Documentation of somnolence, stupor and coma in diabetes moves the case to E13; the two are not reported together unless documented as unrelated.

  Full comparison: R40.2434 vs E13 →

• K72— Excludes1 conflict (Excludes1 — generally not reported together)

  Not coded here — the tabular list excludes this pair for the same encounter.

  Not reported together with this code, except where the two conditions are documented as unrelated.

  What moves you there: Documentation of somnolence, stupor and coma in hepatic failure moves the case to K72; the two are not reported together unless documented as unrelated.

  Full comparison: R40.2434 vs K72 →

• E15— Excludes1 conflict (Excludes1 — generally not reported together)

  Not coded here — the tabular list excludes this pair for the same encounter.

  Not reported together with this code, except where the two conditions are documented as unrelated.

  What moves you there: Documentation of somnolence, stupor and coma in hypoglycemia (nondiabetic) moves the case to E15; the two are not reported together unless documented as unrelated.

  Full comparison: R40.2434 vs E15 →

• R40.2430— 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 “Glasgow coma scale score 3-8, unspecified time” takes R40.2430; specificity in the record moves it back here.

  Full comparison: R40.2434 vs R40.2430 →

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.

Decision Points

The directives on this code's own record, as a pre-claim checklist.

1. A 7th character applies in this family. Confirm the documented encounter matches the character assigned. See the official 7th-character definitions and this code’s variants
2. Sequencing: 3 Code First instructions — the underlying condition is sequenced before this code when present. See the Code First notes
3. 4 Excludes1 entries — codes named there are generally not reported together with this code (Guidelines I.A.12.a). See the Excludes1 notes
4. 1 Excludes2 entry — those conditions are not part of this code and may be reported additionally when documented. See the Excludes2 notes

Checklist rows are derived from this code's own official directives; the wording of each check is MedCoder editorial. The official notes themselves are in the sections each row links to.

Verify Before Coding

• Principal-diagnosis restriction. The Medicare Code Editor lists this code as unacceptable as a principal diagnosis: it describes a circumstance influencing health status rather than a current illness or injury being treated. It is valid as a secondary diagnosis.

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 R40.2434 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 4 Excludes1 notes: R40.0 — Somnolence (via R40.2.-), R40.1 — Stupor (via R40.2.-), R41.82 — Altered mental status, unspecified (via R40.-), R55 — Syncope and collapse (via R40.2.-).

These codes’ tabular lists mark this diagnosis as mutually exclusive — not reported together unless the conditions are documented as unrelated.

Referenced by 2 Use Additional Code instructions: T65.85 — Toxic effect of medetomidine (via R40.-), T67.0 — Heatstroke and sunstroke (via R40.-).

These codes instruct coders to additionally report this code when it applies.

MS-DRG Grouper Relationships (FY2026)

Potential MS-DRG participation — not a DRG assignment.

FY2026 MS-DRG: not on the CMS CC/MCC list — as a secondary diagnosis this code does not change MS-DRG severity for that release.

Named in the grouper logic of 1 MS-DRG: DRG 951 (MDC 23).

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

Clinical classification (AHRQ CCSR):SYM010 — Nervous system signs and symptoms.

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

Related Codes

Principal diagnosis restriction (Medicare Code Editor)

Not acceptable as a principal diagnosis on an inpatient claim.

Same CMS-HCC risk category (V28)

CMS maps these diagnoses to the same Hierarchical Condition Category (Coma, Brain Compression/Anoxic Damage) for risk-adjusted payment.

R40.2311 — Coma scale, best motor response, none, in the field [EMT or ambulance], R40.2312 — Coma scale, best motor response, none, at arrival to emergency department, R40.2313 — Coma scale, best motor response, none, at hospital admission, R40.2314 — Coma scale, best motor response, none, 24 hours or more after hospital admission, R40.2320 — Coma scale, best motor response, extension, unspecified time, R40.2321 — Coma scale, best motor response, extension, in the field [EMT or ambulance], R40.2322 — Coma scale, best motor response, extension, at arrival to emergency department, R40.2323 — Coma scale, best motor response, extension, at hospital admission, R40.2324 — Coma scale, best motor response, extension, 24 hours or more after hospital admission, R40.2430 — Glasgow coma scale score 3-8, unspecified time, R40.2431 — Glasgow coma scale score 3-8, in the field [EMT or ambulance], R40.2432 — Glasgow coma scale score 3-8, at arrival to emergency department, R40.2433 — Glasgow coma scale score 3-8, at hospital admission, R40.2440 — Other coma, without documented Glasgow coma scale score, or with partial score reported, unspecified time, R40.2441 — Other coma, without documented Glasgow coma scale score, or with partial score reported, in the field [EMT or ambulance], R40.2442 — Other coma, without documented Glasgow coma scale score, or with partial score reported, at arrival to emergency department, R40.2443 — Other coma, without documented Glasgow coma scale score, or with partial score reported, at hospital admission, R40.2444 — Other coma, without documented Glasgow coma scale score, or with partial score reported, 24 hours or more after hospital admission, R40.2A — Nontraumatic coma due to underlying condition, R40.3 — Persistent vegetative state, +40 more

Related risk categories

These categories interact through CMS's HCC hierarchy — one can suppress the other's risk-adjustment weight when both are present on a claim.

Major Head Injury with Loss of Consciousness > 1 Hour, Major Head Injury with Loss of Consciousness < 1 Hour or Unspecified, Chronic Liver Failure/End-Stage Liver Disorders

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical category (Nervous system signs and symptoms).

R40.2420 — Glasgow coma scale score 9-12, unspecified time, R40.2421 — Glasgow coma scale score 9-12, in the field [EMT or ambulance], R40.2422 — Glasgow coma scale score 9-12, at arrival to emergency department, R40.2423 — Glasgow coma scale score 9-12, at hospital admission, R40.2424 — Glasgow coma scale score 9-12, 24 hours or more after hospital admission, R40.243 — Glasgow coma scale score 3-8, R40.2430 — Glasgow coma scale score 3-8, unspecified time, R40.2431 — Glasgow coma scale score 3-8, in the field [EMT or ambulance], R40.2432 — Glasgow coma scale score 3-8, at arrival to emergency department, R40.2433 — Glasgow coma scale score 3-8, at hospital admission, R40.244 — Other coma, without documented Glasgow coma scale score, or with partial score reported, R40.2440 — Other coma, without documented Glasgow coma scale score, or with partial score reported, unspecified time, R40.2441 — Other coma, without documented Glasgow coma scale score, or with partial score reported, in the field [EMT or ambulance], R40.2442 — Other coma, without documented Glasgow coma scale score, or with partial score reported, at arrival to emergency department, R40.2443 — Other coma, without documented Glasgow coma scale score, or with partial score reported, at hospital admission, R40.2444 — Other coma, without documented Glasgow coma scale score, or with partial score reported, 24 hours or more after hospital admission, R40.4 — Transient alteration of awareness, R41.0 — Disorientation, unspecified, R41.1 — Anterograde amnesia, R41.2 — Retrograde amnesia, +138 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.

Blood Glucose Test, Gamma-glutamyl Transferase (GGT) Test, Hepatitis Testing, Partial Thromboplastin Time (PTT) Test, Prothrombin Time Test and INR (PT/INR), Thyroid Stimulating Hormone (TSH)

Contextual Map

Every relationship of R40.2434 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 R40.2434 with these 6 related codes in Claim Check

Hierarchy

• R00-R99 — Chapter 18: Symptoms, Signs and Abnormal Clinical and Laboratory Findings, Not Elsewhere Classified (R00-R99) (R00-R99)[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• R40-R46 — Symptoms and signs involving cognition, perception, emotional state and behavior[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026

Referenced by Excludes1 notes

• R40.0 — Somnolence[Excludes1](via R40.2.-): “coma (R40.2-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• R40.1 — Stupor[Excludes1](via R40.2.-): “coma (R40.2-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• R41.82 — Altered mental status, unspecified[Excludes1](via R40.-): “altered level of consciousness (R40.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• R55 — Syncope and collapse[Excludes1](via R40.2.-): “unconsciousness NOS (R40.2-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Referenced by Use Additional Code instructions

• T65.85 — Toxic effect of medetomidine[Use Additional Code](via R40.-): “somnolence, stupor and coma (R40.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• T67.0 — Heatstroke and sunstroke[Use Additional Code](via R40.-): “coma and stupor (R40.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Clinical classification (CCSR)

• SYM010 — Nervous system signs and symptoms[CCSR]— AHRQ CCSR for ICD-10-CM Diagnoses (HCUP)

Risk adjustment (CMS-HCC)

• HCC 202 — Coma, Brain Compression/Anoxic Damage [CMS-HCC]— CMS-HCC V28 · 2026

MS-DRG Grouper

• DRG 951 — OTHER FACTORS INFLUENCING HEALTH STATUS[MS-DRG]: “OTHER FACTORS INFLUENCING HEALTH STATUS (MDC 23)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026

MDC crossing

• MDC 23 — Factors Influencing Health Status and Other Contacts with Health Services[MDC crossing]: “Factors Influencing Health Status and Other Contacts with Health Services — 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. 1,235 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2026

Nearest codes (40)

• R40 — Somnolence, stupor and coma[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• R40.2344 — Coma scale, best motor response, flexion withdrawal, 24 hours or more after hospital admission[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• R40.235 — Coma scale, best motor response, localizes pain[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• R40.2350 — Coma scale, best motor response, localizes pain, unspecified time[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• R40.2351 — Coma scale, best motor response, localizes pain, in the field [EMT or ambulance][Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• R40.2352 — Coma scale, best motor response, localizes pain, at arrival to emergency department[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• R40.2353 — Coma scale, best motor response, localizes pain, at hospital admission[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• R40.2354 — Coma scale, best motor response, localizes pain, 24 hours or more after hospital admission[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• and 32 more

Change history

• FY2017 — Added to the code set[Change history]— CMS release files (code change ledger) · icd10cm-fy2017

Common coding questions

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

Coding guidelines Official source data

ICD-10-CM Official Guidelines for Coding and Reporting (FY2026), quoted by section 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 R40.2434 in its code family, with their registry titles.

• R40.243 — Glasgow coma scale score 3-8
• R40.2430 — Glasgow coma scale score 3-8, unspecified time
• R40.2431 — Glasgow coma scale score 3-8, in the field [EMT or ambulance]
• R40.2432 — Glasgow coma scale score 3-8, at arrival to emergency department
• R40.2433 — Glasgow coma scale score 3-8, at hospital admission
• R40.244 — Other coma, without documented Glasgow coma scale score, or with partial score reported
• R40.2440 — Other coma, without documented Glasgow coma scale score, or with partial score reported, unspecified time
• R40.2441 — Other coma, without documented Glasgow coma scale score, or with partial score reported, in the field [EMT or ambulance]
• R40.2442 — Other coma, without documented Glasgow coma scale score, or with partial score reported, at arrival to emergency department
• R40.2443 — Other coma, without documented Glasgow coma scale score, or with partial score reported, at hospital admission

View all codes in the R40 family