ICD10BillableValid for clinical use
ICD-10 Code G04.91: Myelitis, unspecified
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 myelitis, unspecified 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
G00-G09Inflammatory diseases of the central nervous system
category
G04Encephalitis, myelitis and encephalomyelitis
category
G04.9Encephalitis, myelitis and encephalomyelitis, unspecified
currentG04.9
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
CPT 87483high
INFECTIOUS AGENT DETECTION BY NUCLEIC ACID (DNA OR RNA); CENTRAL NERVOUS SYSTEM PATHOGEN (EG, NEISSERIA MENINGITIDIS, STREPTOCOCCUS PNEUMONIAE, LISTERIA, HAEMOPHILUS INFLUENZAE, E. COLI, STREPTOCOCCUS AGALACTIAE, ENTEROVIRUS, HUMAN PARECHOVIRUS, HERPES SIMPLEX VIRUS TYPE 1 AND 2, HUMAN HERPESVIRUS 6, CYTOMEGALOVIRUS, VARICELLA ZOSTER VIRUS, CRYPTOCOCCUS), INCLUDES MULTIPLEX REVERSE TRANSCRIPTION, WHEN PERFORMED, AND MULTIPLEX AMPLIFIED PROBE TECHNIQUE, MULTIPLE TYPES OR SUBTYPES, 12-25 TARGETS
Source: CMS coverage guidance
CPT 51726high
COMPLEX CYSTOMETROGRAM (IE, CALIBRATED ELECTRONIC EQUIPMENT);
Source: CMS coverage guidance
CPT 51727high
COMPLEX CYSTOMETROGRAM (IE, CALIBRATED ELECTRONIC EQUIPMENT); WITH URETHRAL PRESSURE PROFILE STUDIES (IE, URETHRAL CLOSURE PRESSURE PROFILE), ANY TECHNIQUE
Source: CMS coverage guidance
CPT 51729high
COMPLEX CYSTOMETROGRAM (IE, CALIBRATED ELECTRONIC EQUIPMENT); WITH VOIDING PRESSURE STUDIES (IE, BLADDER VOIDING PRESSURE) AND URETHRAL PRESSURE PROFILE STUDIES (IE, URETHRAL CLOSURE PRESSURE PROFILE), ANY TECHNIQUE
Source: CMS coverage guidance
CPT 51728high
COMPLEX CYSTOMETROGRAM (IE, CALIBRATED ELECTRONIC EQUIPMENT); WITH VOIDING PRESSURE STUDIES (IE, BLADDER VOIDING PRESSURE), ANY TECHNIQUE
Source: CMS coverage guidance
CPT 51741high
COMPLEX UROFLOWMETRY (EG, CALIBRATED ELECTRONIC EQUIPMENT)
Source: CMS coverage guidance
Coding guidelines
Common synonyms
Myelitis, unspecifiedMyelitis
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.