Alphabetic Index FY2027

G36.0

Neuromyelitis optica [Devic]

FY2027Chapter 6: Diseases of the nervous system/G35–G37 Demyelinating diseases of the central nervous system

BillableComplete code, valid to report
Care settingsHome Health Primary · Neuro RehabilitationIRF 60% RuleHospital CC

G36.0 (also written G360) is a billable ICD-10-CM diagnosis code for neuromyelitis optica [Devic]. It is part of the FY2027 code set, effective October 1, 2026. It is one of the 4 codes in category G36 (Other acute disseminated demyelination). The Alphabetic Index lists it under 9 entries. Its coding notes include 1 Excludes1 entry and 9 Excludes2 entries.

Excludes1

Not coded here. The listed conditions generally should not be reported together.

Inherited from G36 Other acute disseminated demyelination
  • postinfectious encephalitis and encephalomyelitis NOS (G04.01)

Excludes2

Not included here. Both codes may be reported if the patient has both conditions.

This code
  • optic neuritis NOS (H46)
Also from chapter/block level (8 notes)
Inherited from Chapter 6 Diseases of the nervous system
  • 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.

Home Health Primary

Accepted as the primary (principal) diagnosis on a home health claim. The Home Health Grouper assigns it to the Neuro Rehabilitation clinical group.

Source: CMS Home Health Grouper Software v07.2.26, effective October 1, 2026

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, 2026

Hospital CC

Counts as a complication or comorbidity (CC) when reported as a secondary diagnosis on an inpatient claim. It does not count when the principal diagnosis is one of the 9 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 C

Inclusion terms

Conditions classified to this code.

This code
  • Demyelination in optic neuritis

Alphabetic Index terms

Terms the official Alphabetic Index lists for this code. 9 entries