ICD10BillableValid for clinical use
ICD-10 Code G40.919: Epilepsy, unspecified, intractable, without status epilepticus
G40.919 is a billable ICD-10 diagnosis code used to classify Epilepsy, unspecified, intractable, without status epilepticus 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 Diseases of the nervous system (G00-G99).
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 Diseases of the nervous system (G00-G99).
When is it used?
- May be used when a clinician documents epilepsy, unspecified, intractable, without status epilepticus 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
6Diseases of the nervous system (G00-G99)
block
G40-G47Episodic and paroxysmal disorders
category
G40Epilepsy and recurrent seizures
category
G40.9Epilepsy, unspecified
category
G40.91Epilepsy, unspecified, intractable
currentG40.91
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
NeurologistGeneral Physician
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
Epilepsy, unspecified, intractable, without status epilepticusEpilepsy, unspecified, intractable
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.