Alphabetic Index FY2027

R83

Abnormal findings in cerebrospinal fluid

FY2027Chapter 18: Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified/R83–R89 Abnormal findings on examination of other body fluids, substances and tissues, without diagnosis

Non-billable headerNot valid on its own. Use one of the more specific codes under it.

R83 is a non-billable ICD-10-CM code category for abnormal findings in cerebrospinal fluid. Report a more specific code from it instead. It is part of the FY2027 code set, effective October 1, 2026. The more specific codes under it are 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 and 5 more. Its coding notes include 2 Excludes1 entries and 7 Excludes2 entries.

Guidelines tip

From the FY2027 Official Guidelines. ICD10Ref adds no rules of its own.

Symptom and sign codes are acceptable when no definitive diagnosis has been established. They are not added for signs that are routinely associated with a diagnosis.

Guidelines I.C.18.a; I.C.18.bSymptom and sign codesRead the official text

Excludes1

Not coded here. The listed conditions generally should not be reported together.

Also from chapter/block level (2 notes)
Inherited from R83–R89 Abnormal findings on examination of other body fluids, substances and tissues, without diagnosis
  • abnormal findings on antenatal screening of mother (O28.-)
  • diagnostic abnormal findings classified elsewhere - see Alphabetical Index

Excludes2

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

Also from chapter/block level (7 notes)
Inherited from R83–R89 Abnormal findings on examination of other body fluids, substances and tissues, without diagnosis
  • abnormal findings on examination of blood, without diagnosis (R70-R79)
  • abnormal findings on examination of urine, without diagnosis (R80-R82)
  • abnormal tumor markers (R97.-)
Inherited from Chapter 18 Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified
  • abnormal findings on antenatal screening of mother (O28.-)
  • certain conditions originating in the perinatal period (P04-P96)
  • signs and symptoms classified in the body system chapters
  • signs and symptoms of breast (N63, N64.5)

Notes

Also from chapter/block level (9 notes)
Inherited from Chapter 18 Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified
  • This chapter includes symptoms, signs, abnormal results of clinical or other investigative procedures, and ill-defined conditions regarding which no diagnosis classifiable elsewhere is recorded.
  • Signs and symptoms that point rather definitely to a given diagnosis have been assigned to a category in other chapters of the classification. In general, categories in this chapter include the less well-defined conditions and symptoms that, without the necessary study of the case to establish a final diagnosis, point perhaps equally to two or more diseases or to two or more systems of the body. Practically all categories in the chapter could be designated 'not otherwise specified', 'unknown etiology' or 'transient'. The Alphabetical Index should be consulted to determine which symptoms and signs are to be allocated here and which to other chapters. The residual subcategories, numbered .8, are generally provided for other relevant symptoms that cannot be allocated elsewhere in the classification.
  • The conditions and signs or symptoms included in categories R00-R94 consist of:
    • (a) cases for which no more specific diagnosis can be made even after all the facts bearing on the case have been investigated;
    • (b) signs or symptoms existing at the time of initial encounter that proved to be transient and whose causes could not be determined;
    • (c) provisional diagnosis in a patient who failed to return for further investigation or care;
    • (d) cases referred elsewhere for investigation or treatment before the diagnosis was made;
    • (e) cases in which a more precise diagnosis was not available for any other reason;
    • (f) certain symptoms, for which supplementary information is provided, that represent important problems in medical care in their own right.

More specific codes under R83 9