ICD10BillableValid for clinical use
ICD-10 Code R40.2A: Nontraumatic coma due to underlying condition
R40.2A is a billable ICD-10 diagnosis code used to classify Nontraumatic coma due to underlying condition in medical records and claims. You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records. ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99).
Reviewed by HealthAssure Clinical TeamUpdated 26 May 2026
What is this code?
ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99).
When is it used?
- May be used when a clinician documents nontraumatic coma due to underlying condition in a patient's medical record.
- May appear in hospital records, claims, referrals, and clinical documentation.
- This code can be used as a clinically usable diagnosis entry in standardized coding workflows.
What it does not mean
- A code alone does not explain severity, treatment plan, or outcome.
- A medical code should not be treated as a substitute for a doctor's diagnosis or advice.
Code hierarchy
chapter
18Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99)
block
R40-R46Symptoms and signs involving cognition, perception, emotional state and behavior
category
R40Somnolence, stupor and coma
category
R40.2Coma
currentR40.2
Official coding notes
Inclusion terms
- Secondary coma
Applicable to
- underlying condition
Excludes1 (do not code together)
- coma scale, best motor response (R40.24.-)
- coma scale, best verbal response (R40.22.-)
- coma scale, eyes open (R40.21.-)
- Glasgow coma scale, total score (R40.23.-)
Code first
- underlying condition
Where you may see this code
You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records.
Related specialists
General PhysicianOrthopedic Specialist
Related codes
Sibling codes
Coverage-related procedures and services
HCPCS G0480high
DRUG TEST(S), DEFINITIVE, UTILIZING (1) DRUG IDENTIFICATION METHODS ABLE TO IDENTIFY INDIVIDUAL DRUGS AND DISTINGUISH BETWEEN STRUCTURAL ISOMERS (BUT NOT NECESSARILY STEREOISOMERS), INCLUDING, BUT NOT LIMITED TO GC/MS (ANY TYPE, SINGLE OR TANDEM) AND LC/MS (ANY TYPE, SINGLE OR TANDEM AND EXCLUDING IMMUNOASSAYS (E.G., IA, EIA, ELISA, EMIT, FPIA) AND ENZYMATIC METHODS (E.G., ALCOHOL DEHYDROGENASE)), (2) STABLE ISOTOPE OR OTHER UNIVERSALLY RECOGNIZED INTERNAL STANDARDS IN ALL SAMPLES (E.G., TO CONTROL FOR MATRIX EFFECTS, INTERFERENCES AND VARIATIONS IN SIGNAL STRENGTH), AND (3) METHOD OR DRUG-SPECIFIC CALIBRATION AND MATRIX-MATCHED QUALITY CONTROL MATERIAL (E.G., TO CONTROL FOR INSTRUMENT VARIATIONS AND MASS SPECTRAL DRIFT); QUALITATIVE OR QUANTITATIVE, ALL SOURCES, INCLUDES SPECIMEN VALIDITY TESTING, PER DAY; 1-7 DRUG CLASS(ES), INCLUDING METABOLITE(S) IF PERFORMED
Source: CMS coverage guidance
HCPCS G0482high
DRUG TEST(S), DEFINITIVE, UTILIZING (1) DRUG IDENTIFICATION METHODS ABLE TO IDENTIFY INDIVIDUAL DRUGS AND DISTINGUISH BETWEEN STRUCTURAL ISOMERS (BUT NOT NECESSARILY STEREOISOMERS), INCLUDING, BUT NOT LIMITED TO GC/MS (ANY TYPE, SINGLE OR TANDEM) AND LC/MS (ANY TYPE, SINGLE OR TANDEM AND EXCLUDING IMMUNOASSAYS (E.G., IA, EIA, ELISA, EMIT, FPIA) AND ENZYMATIC METHODS (E.G., ALCOHOL DEHYDROGENASE)), (2) STABLE ISOTOPE OR OTHER UNIVERSALLY RECOGNIZED INTERNAL STANDARDS IN ALL SAMPLES (E.G., TO CONTROL FOR MATRIX EFFECTS, INTERFERENCES AND VARIATIONS IN SIGNAL STRENGTH), AND (3) METHOD OR DRUG-SPECIFIC CALIBRATION AND MATRIX-MATCHED QUALITY CONTROL MATERIAL (E.G., TO CONTROL FOR INSTRUMENT VARIATIONS AND MASS SPECTRAL DRIFT); QUALITATIVE OR QUANTITATIVE, ALL SOURCES, INCLUDES SPECIMEN VALIDITY TESTING, PER DAY; 15-21 DRUG CLASS(ES), INCLUDING METABOLITE(S) IF PERFORMED
Source: CMS coverage guidance
HCPCS G0483high
DRUG TEST(S), DEFINITIVE, UTILIZING (1) DRUG IDENTIFICATION METHODS ABLE TO IDENTIFY INDIVIDUAL DRUGS AND DISTINGUISH BETWEEN STRUCTURAL ISOMERS (BUT NOT NECESSARILY STEREOISOMERS), INCLUDING, BUT NOT LIMITED TO GC/MS (ANY TYPE, SINGLE OR TANDEM) AND LC/MS (ANY TYPE, SINGLE OR TANDEM AND EXCLUDING IMMUNOASSAYS (E.G., IA, EIA, ELISA, EMIT, FPIA) AND ENZYMATIC METHODS (E.G., ALCOHOL DEHYDROGENASE)), (2) STABLE ISOTOPE OR OTHER UNIVERSALLY RECOGNIZED INTERNAL STANDARDS IN ALL SAMPLES (E.G., TO CONTROL FOR MATRIX EFFECTS, INTERFERENCES AND VARIATIONS IN SIGNAL STRENGTH), AND (3) METHOD OR DRUG-SPECIFIC CALIBRATION AND MATRIX-MATCHED QUALITY CONTROL MATERIAL (E.G., TO CONTROL FOR INSTRUMENT VARIATIONS AND MASS SPECTRAL DRIFT); QUALITATIVE OR QUANTITATIVE, ALL SOURCES, INCLUDES SPECIMEN VALIDITY TESTING, PER DAY; 22 OR MORE DRUG CLASS(ES), INCLUDING METABOLITE(S) IF PERFORMED
Source: CMS coverage guidance
HCPCS G0481high
DRUG TEST(S), DEFINITIVE, UTILIZING (1) DRUG IDENTIFICATION METHODS ABLE TO IDENTIFY INDIVIDUAL DRUGS AND DISTINGUISH BETWEEN STRUCTURAL ISOMERS (BUT NOT NECESSARILY STEREOISOMERS), INCLUDING, BUT NOT LIMITED TO GC/MS (ANY TYPE, SINGLE OR TANDEM) AND LC/MS (ANY TYPE, SINGLE OR TANDEM AND EXCLUDING IMMUNOASSAYS (E.G., IA, EIA, ELISA, EMIT, FPIA) AND ENZYMATIC METHODS (E.G., ALCOHOL DEHYDROGENASE)), (2) STABLE ISOTOPE OR OTHER UNIVERSALLY RECOGNIZED INTERNAL STANDARDS IN ALL SAMPLES (E.G., TO CONTROL FOR MATRIX EFFECTS, INTERFERENCES AND VARIATIONS IN SIGNAL STRENGTH), AND (3) METHOD OR DRUG-SPECIFIC CALIBRATION AND MATRIX-MATCHED QUALITY CONTROL MATERIAL (E.G., TO CONTROL FOR INSTRUMENT VARIATIONS AND MASS SPECTRAL DRIFT); QUALITATIVE OR QUANTITATIVE, ALL SOURCES, INCLUDES SPECIMEN VALIDITY TESTING, PER DAY; 8-14 DRUG CLASS(ES), INCLUDING METABOLITE(S) IF PERFORMED
Source: CMS coverage guidance
HCPCS G0659high
DRUG TEST(S), DEFINITIVE, UTILIZING DRUG IDENTIFICATION METHODS ABLE TO IDENTIFY INDIVIDUAL DRUGS AND DISTINGUISH BETWEEN STRUCTURAL ISOMERS (BUT NOT NECESSARILY STEREOISOMERS), INCLUDING BUT NOT LIMITED TO GC/MS (ANY TYPE, SINGLE OR TANDEM) AND LC/MS (ANY TYPE, SINGLE OR TANDEM), EXCLUDING IMMUNOASSAYS (E.G., IA, EIA, ELISA, EMIT, FPIA) AND ENZYMATIC METHODS (E.G., ALCOHOL DEHYDROGENASE), PERFORMED WITHOUT METHOD OR DRUG-SPECIFIC CALIBRATION, WITHOUT MATRIX-MATCHED QUALITY CONTROL MATERIAL, OR WITHOUT USE OF STABLE ISOTOPE OR OTHER UNIVERSALLY RECOGNIZED INTERNAL STANDARD(S) FOR EACH DRUG, DRUG METABOLITE OR DRUG CLASS PER SPECIMEN; QUALITATIVE OR QUANTITATIVE, ALL SOURCES, INCLUDES SPECIMEN VALIDITY TESTING, PER DAY, ANY NUMBER OF DRUG CLASSES
Source: CMS coverage guidance
CPT 80307high
DRUG TEST(S), PRESUMPTIVE, ANY NUMBER OF DRUG CLASSES, ANY NUMBER OF DEVICES OR PROCEDURES; BY INSTRUMENT CHEMISTRY ANALYZERS (EG, UTILIZING IMMUNOASSAY [EG, EIA, ELISA, EMIT, FPIA, IA, KIMS, RIA]), CHROMATOGRAPHY (EG, GC, HPLC), AND MASS SPECTROMETRY EITHER WITH OR WITHOUT CHROMATOGRAPHY, (EG, DART, DESI, GC-MS, GC-MS/MS, LC-MS, LC-MS/MS, LDTD, MALDI, TOF) INCLUDES SAMPLE VALIDATION WHEN PERFORMED, PER DATE OF SERVICE
Source: CMS coverage guidance
Coding guidelines
Common synonyms
Nontraumatic coma due to underlying condition
Frequently asked questions
About this content
This page is prepared by HealthAssure's clinical team using official coding standards from ICD-10. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.