323 Encephalitis, myelitis, and encephalomyelitis (323.01-323.9) ICD-9-CM
The 323.01-323.9 block classified 323 encephalitis, myelitis, and encephalomyelitis with 16 legacy diagnosis codes. None remain valid for claim submission; each code below links to its reference page with the official ICD-10-CM replacement under the CMS General Equivalence Mappings.
Retired Code Set
ICD-9-CM stopped being valid for U.S. claims with dates of service on or after October 1, 2015, when ICD-10-CM replaced it. Use this index for historical lookups and crosswalking; for current coding, start from the ICD-10-CM codes list or the ICD-9 / ICD-10 converter.
Legacy Codes in the 323.01-323.9 Block 16 codes
None of these codes remain valid for claim submission. Each code page shows its ICD-10-CM replacement under the CMS General Equivalence Mappings.
- 323.01 Enceph/encephmye oth dis
- 323.02 Myelitis-oth viral dis
- 323.1 Rickettsial encephalitis
- 323.2 Protozoal encephalitis
- 323.41 Ot encph/mye ot inf else
- 323.42 Oth myelitis ot inf else
- 323.51 Enceph/myel folwg immune
- 323.52 Myelitis follwg immune
- 323.61 Inf ac dis encephalomyel
- 323.62 Postinf encephalitis NEC
- 323.63 Postinfectious myelitis
- 323.71 Toxic encph & encephlomy
- 323.72 Toxic myelitis
- 323.81 Enceph & encephlalo NEC
- 323.82 Myelitis cause NEC
- 323.9 Encephalitis NOS
Questions About This Page
Are the 323.01-323.9 codes still billable?
No. Every code in this block became invalid for U.S. claims after September 30, 2015. Each code page linked above shows the ICD-10-CM replacement CMS assigned in the General Equivalence Mappings, and the ICD-9 / ICD-10 converter translates any of them directly.
What did the 323.01-323.9 block classify?
The block classified 323 encephalitis, myelitis, and encephalomyelitis with 16 codes in the final ICD-9-CM release. It sat under Diseases of the nervous system (320–359) in the legacy hierarchy.
Related References
Source: final CMS ICD-9-CM release (version date October 1, 2014). Retired from U.S. claims after September 30, 2015.
