R83.5 Abnormal microbiological findings in cerebrospinal fluid

ICD-10-CM R83.5: Abnormal Microbiological Findings in Cerebrospinal Fluid

ICD-10-CM code R83.5 identifies abnormal microbiological findings in cerebrospinal fluid, the liquid surrounding the brain and spinal cord. It is a billable code within the broader category of abnormal cerebrospinal fluid findings, classified by its semantic type as a finding within the ICD-10-CM terminology structure. 1 2 5

Plain-language overview

Cerebrospinal fluid surrounds the brain and spinal cord, and clinical teams collect samples of this fluid to measure pressures and perform further laboratory testing. 2

The ICD-10-CM terminology assigns the preferred name abnormal microbiological findings in cerebrospinal fluid to code R83.5, maintaining an active record status. 1

What this code represents

Code R83.5 is classified by its semantic type as a finding within the ICD-10-CM terminology structure, and it falls under category R83 for abnormal findings in cerebrospinal fluid. 1 5

This code is part of the section covering abnormal findings on examination of other body fluids, substances and tissues, without diagnosis, which is within Chapter 18 of the ICD-10-CM system. 5

Coding details

In the April 2026 reference data, R83.5 has no child codes and is presented as a billable, specific code within Chapter 18, covering symptoms, signs, and abnormal clinical and laboratory findings. 5

The April 2026 reference data for R83.5 lists no code first instruction and no use additional code instruction for this specific cerebrospinal fluid finding. 5

Documentation considerations

Cerebrospinal fluid collection for testing occurs via methods like lumbar puncture, cisternal puncture, or through existing tubes such as a shunt or ventricular drain. 2

What the sources add

While the terminology record identifies R83.5 as having narrower concepts, the April 2026 reference data explicitly states R83.5 has no child codes and functions as a billable code. 1 5

A phecode mapping groups abnormal microbiological findings in cerebrospinal fluid with other abnormal cerebrospinal fluid findings, including nonspecific, cytological, and immunological abnormalities. 3

Sources

1. ICD-10-CM R83.5 terminology record — National Cancer Institute Enterprise Vocabulary Services; accessed 2026-07-27.
2. Cerebrospinal fluid (CSF) collection: MedlinePlus Medical Encyclopedia — medlineplus.gov; accessed 2026-07-27.
3. Phecode 346.3 · Cancer PRSweb — csg.sph.umich.edu; accessed 2026-07-27.
4. EVS Explore — evsexplore.semantics.cancer.gov; accessed 2026-07-27.
5. ICD-10-CM Code R83.5 | Vero — veroscribe.com; accessed 2026-07-27.