G05.4
Myelitis in diseases classified elsewhere
G05.4 (also written G054) is a billable ICD-10-CM diagnosis code for myelitis in diseases classified elsewhere. It is part of the FY2027 code set, effective October 1, 2026. It is one of the 2 codes in category G05 (Encephalitis, myelitis and encephalomyelitis in diseases classified elsewhere). The Alphabetic Index lists it under 2 entries. Its coding notes include a Code first instruction, 11 Excludes1 entries and 8 Excludes2 entries.
Code first
If the underlying condition listed here is present and known, sequence it first.
- underlying disease, such as:
- congenital toxoplasmosis encephalitis, myelitis and encephalomyelitis (P37.1)
- cytomegaloviral encephalitis, myelitis and encephalomyelitis (B25.8)
- encephalitis, myelitis and encephalomyelitis (in) systemic lupus erythematosus (M32.19)
- eosinophilic meningoencephalitis (B83.2)
- human immunodeficiency virus [HIV] disease (B20)
- poliovirus (A80.-)
- suppurative otitis media (H66.01-H66.4)
- systemic lupus erythematosus (M32.19)
- trichinellosis (B75)
Excludes1
Not coded here. The listed conditions generally should not be reported together.
- adenoviral encephalitis, myelitis and encephalomyelitis (A85.1)
- encephalitis, myelitis and encephalomyelitis (in) measles (B05.0)
- enteroviral encephalitis, myelitis and encephalomyelitis (A85.0)
- herpesviral [herpes simplex] encephalitis, myelitis and encephalomyelitis (B00.4)
- listerial encephalitis, myelitis and encephalomyelitis (A32.12)
- meningococcal encephalitis, myelitis and encephalomyelitis (A39.81)
- mumps encephalitis, myelitis and encephalomyelitis (B26.2)
- postchickenpox encephalitis, myelitis and encephalomyelitis (B01.1-)
- rubella encephalitis, myelitis and encephalomyelitis (B06.01)
- toxoplasmosis encephalitis, myelitis and encephalomyelitis (B58.2)
- zoster encephalitis, myelitis and encephalomyelitis (B02.0)
Excludes2
Not included here. Both codes may be reported if the patient has both conditions.
Also from chapter/block level (8 notes)
- certain conditions originating in the perinatal period (P04-P96)
- certain infectious and parasitic diseases (A00-B99)
- complications of pregnancy, childbirth and the puerperium (O00-O9A)
- congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
- endocrine, nutritional and metabolic diseases (E00-E88)
- injury, poisoning and certain other consequences of external causes (S00-T88)
- neoplasms (C00-D49)
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
Care settings
How CMS programs treat this code. These are CMS claim edits and list entries, not coverage or eligibility rules.
Hospice: not accepted as primary
Not accepted as the principal diagnosis on a hospice claim (bill types 081x and 082x). The Integrated OCE returns an edit for this code.
Reason: Manifestation code. Report the underlying condition first (see the Code first note).
Hospital MCC
Counts as a major complication or comorbidity (MCC) when reported as a secondary diagnosis on an inpatient claim. It does not count when the principal diagnosis is one of the 182 codes in its exclusion list. Some MS-DRGs also ignore a CC or MCC that defines the DRG.
Source: CMS MS-DRG Definitions Manual v44, effective October 1, 2026, Appendix CInclusion terms
Conditions classified to this code.
- Meningomyelitis in diseases classified elsewhere
Alphabetic Index terms
Terms the official Alphabetic Index lists for this code. 2 entries