Abnormal findings in cerebrospinal fluid (R83) ICD-10-CM
The R83 code range covers abnormal findings in cerebrospinal fluid with 10 ICD-10-CM diagnosis codes. 9 of them are billable and valid for claim submission in fiscal year 2026, and the category headers group them but cannot themselves be billed.
Codes in the R83 Range 10 codes · 9 billable
- R83 Abnormal findings in cerebrospinal fluidNon-billable
- R83.0 Abnormal level of enzymes in cerebrospinal fluid
- R83.1 Abnormal level of hormones in cerebrospinal fluid
- R83.2 Abnormal level of other drugs, medicaments and biological substances in cerebrospinal fluid
- R83.3 Abnormal level of substances chiefly nonmedicinal as to source in cerebrospinal fluid
- R83.4 Abnormal immunological findings in cerebrospinal fluid
- R83.5 Abnormal microbiological findings in cerebrospinal fluid
- R83.6 Abnormal cytological findings in cerebrospinal fluid
- R83.8 Other abnormal findings in cerebrospinal fluid
- R83.9 Unspecified abnormal finding in cerebrospinal fluid
About the R83 Code Range
The ICD-10 code R83 section is used to record abnormal findings in cerebrospinal fluid (CSF) without assigning a specific diagnosis. These codes help identify various unusual lab results detected during CSF analysis.
This section includes detailed codes for specific abnormal CSF components: R83.0 for enzyme levels outside the normal range, R83.1 for hormone imbalances, and R83.2 and R83.3 for abnormal levels of drugs or other substances. Immunological abnormalities in CSF are captured with R83.4, while microbiological findings such as microorganisms identified in the fluid are coded under R83.5. Cytological abnormalities, involving abnormal cell counts or types (e.g., pleocytosis or lymphocytosis), use R83.6. Other miscellaneous abnormal CSF findings—like altered protein, glucose, chloride levels, or unusual fluid appearance—are classified under R83.8. When findings are abnormal but unspecified, R83.9 applies.
For medical coders looking for the ICD-10 code for abnormal findings in cerebrospinal fluid, referencing these subcodes is essential to accurately capture the nature of the CSF abnormalities reported in diagnostic testing.
Questions About This Page
How many billable codes are in the R83 range?
Of the 10 codes in this range, 9 are billable and valid for claim submission from October 1, 2025 through September 30, 2026. Category header codes group them but cannot be reported on claims.
What does the R83 range classify?
The range classifies abnormal findings in cerebrospinal fluid. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.
Related References
Source: CMS FY 2026 ICD-10-CM Tabular List and order file, effective October 1, 2025 through September 30, 2026.
