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ICD-10-CM tabular list

Chapter 18: Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified

R00-R99

Chapter 18 of the ICD-10-CM tabular list covers symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified, codes R00-R99. It holds 962 codes across 14 blocks, of which 773 are billable and 189 are header codes that cannot go on a claim. 118 (12%) require a 7th character.

Excludes2 — not included here, but may coexist

The excluded condition is not part of this code, but a patient can have both. You may code both.

  • 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

Additional guidance from the ICD-10-CM tabular list.

  • 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.

Risk adjustment in Chapter 18

60 of this chapter’s codes map to a CMS-HCC, which means the diagnosis carries a risk-adjustment payment when it is documented and coded to the level the record supports.

  • HCC 202 Coma, Brain Compression/Anoxic Damage
  • HCC 2 Septicemia, Sepsis, Systemic Inflammatory Response Syndrome/Shock
  • HCC 201 Seizure Disorders and Convulsions
  • HCC 213 Cardio-Respiratory Failure and Shock
  • HCC 155 Major Depression, Moderate or Severe, without Psychosis
  • HCC 180 Quadriplegia

Blocks in this chapter

ICD-10-CMFY2026-Apr· effective April 1, 2026