G13.8

Systemic atrophy primarily affecting central nervous system in other diseases classified elsewhere

FY2027Chapter 6: Diseases of the nervous system/G10–G14 Systemic atrophies primarily affecting the central nervous system

BillableComplete code, valid to report

G13.8 (also written G138) is a billable ICD-10-CM diagnosis code for systemic atrophy primarily affecting central nervous system in other diseases classified elsewhere. It is part of the FY2027 code set, effective October 1, 2026. It is one of the 4 codes in category G13 (Systemic atrophies primarily affecting central nervous system in diseases classified elsewhere). The Alphabetic Index lists it under 1 entry. 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.

This code
  • underlying disease

Excludes2

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

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.

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).

Source: CMS Integrated Outpatient Code Editor (IOCE) v27.3, effective October 1, 2026, edit 86

IPF Primary

IPF MS-DRG adjustment. A principal diagnosis of this code groups to one of these MS-DRGs. Which one depends on other facts of the stay, so the factor is a range:

MS-DRGDescriptionFactor
056Degenerative nervous system disorders w MCC1.12
057Degenerative nervous system disorders w/o MCC1.11
A principal diagnosis that groups to none of the 19 designated MS-DRGs gets no MS-DRG adjustment. Otherwise the claim still receives the federal per diem base rate and the other adjustments.

Source: CMS IPF PPS FY 2027 final rule (CMS-1847-F), Addendum A; code lists from the CMS MS-DRG Definitions Manual v44; effective for discharges on or after October 1, 2026

Alphabetic Index terms

Terms the official Alphabetic Index lists for this code. 1 entry