G09
Sequelae of inflammatory diseases of central nervous system
G09 is a billable ICD-10-CM diagnosis code for sequelae of inflammatory diseases of central nervous system. It is part of the FY2027 code set, effective October 1, 2026. The Alphabetic Index lists it under 14 entries. Its coding notes include a Code first instruction and 8 Excludes2 entries.
Code first
If the underlying condition listed here is present and known, sequence it first.
- condition resulting from (sequela) of inflammatory diseases of central nervous system
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.
IRF 60% Rule
On the CMS list of diagnoses used to determine presumptive compliance with the IRF 60 percent rule.
Source: CMS IRF Presumptive Compliance-3, FY 2027 IRF PPS final rule files, effective for discharges on or after October 1, 2026Notes
- Category G09 is to be used to indicate conditions whose primary classification is to G00-G08 as the cause of sequelae, themselves classifiable elsewhere. The 'sequelae' include conditions specified as residuals.
Alphabetic Index terms
Terms the official Alphabetic Index lists for this code. 14 entries
- Abscess (connective tissue) (embolic) (fistulous) (infective) (metastatic) (multiple) (pernicious) (pyogenic) (septic), cerebellum, cerebellar, sequelae
- Abscess (connective tissue) (embolic) (fistulous) (infective) (metastatic) (multiple) (pernicious) (pyogenic) (septic), cerebral (embolic), sequelae
- Abscess (connective tissue) (embolic) (fistulous) (infective) (metastatic) (multiple) (pernicious) (pyogenic) (septic), extradural, brain, sequelae
- Abscess (connective tissue) (embolic) (fistulous) (infective) (metastatic) (multiple) (pernicious) (pyogenic) (septic), subdural, brain, sequelae
- Parencephalitis, sequelae
- Sequelae (of), abscess, intracranial or intraspinal (conditions in G06)
- Sequelae (of), encephalitis or encephalomyelitis (conditions in G04)
- Sequelae (of), infection, pyogenic, intracranial or intraspinal
- Sequelae (of), meningitis, bacterial (conditions in G00)
- Sequelae (of), meningitis, other or unspecified cause (conditions in G03)
- Sequelae (of), phlebitis or thrombophlebitis of intracranial or intraspinal venous sinuses and veins (conditions in G08)
- Suppuration, suppurative, brain, sequelae