2026 ICD-10-CM Diagnosis Code R83Abnormal findings in cerebrospinal fluid

ICD-10-CM Codes›R00–R99›R83-R89›R83

ICD-10-CM R83
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

R83 is a non-billable ICD-10-CM category code for abnormal findings in cerebrospinal fluid, so it cannot be submitted on claims. Use a more specific code from this category instead, such as R83.0, R83.1, R83.2, and R83.3. As a symptom code, it should not be used as a principal diagnosis once a related definitive diagnosis has been established.

Code Identity

ICD-10-CM Code
R83
Billable Status
No — Non-Billable Category
Code Describes
Abnormal findings in cerebrospinal fluid
Short Description
Abnormal findings in cerebrospinal fluid
Same as the full description in the CMS dataset.
Chapter
R83-R89
Abnormal findings on examination of other body fluids, substances and tissues, without diagnosis

Code Classification

ChapterR00–R99Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified
SectionR83-R89Abnormal findings on examination of other body fluids, substances and tissues, without diagnosis
CategoryR83Abnormal findings in cerebrospinal fluid
This CodeR83Abnormal findings in cerebrospinal fluid

Specific Coding for Abnormal findings in cerebrospinal fluidOverview

Non-specific codes like R83 require more characters. Use one of these billable codes instead:

  • Use R83.0 for Abnormal level of enzymes in cerebrospinal fluid

  • Use R83.1 for Abnormal level of hormones in cerebrospinal fluid

  • Use R83.2 for Abnormal level of other drugs, medicaments and biological substances in cerebrospinal fluid

  • Use R83.3 for Abnormal level of substances chiefly nonmedicinal as to source in cerebrospinal fluid

  • Use R83.4 for Abnormal immunological findings in cerebrospinal fluid

  • Use R83.5 for Abnormal microbiological findings in cerebrospinal fluid

  • Use R83.6 for Abnormal cytological findings in cerebrospinal fluid

  • Use R83.8 for Other abnormal findings in cerebrospinal fluid

  • Use R83.9 for Unspecified abnormal finding in cerebrospinal fluid

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About R83Overview

Is R83 (Abnormal findings in cerebrospinal fluid) a billable code?

No. This is a category header that groups the codes for abnormal findings in cerebrospinal fluid, and headers cannot be submitted on claims. Claims for abnormal findings in cerebrospinal fluid need a more specific code from this category, such as R83.0, R83.1, and R83.2.

Can R83 be a principal diagnosis?

Use it with care. This is a symptom code, so once a definitive diagnosis explaining the abnormal findings in cerebrospinal fluid is established, that condition takes the principal position instead.