2027 ICD-10-CM Diagnosis Code R79Other abnormal findings of blood chemistry

ICD-10-CM Codes›R00–R99›R70-R79›R79

ICD-10-CM R79
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

R79 is a non-billable ICD-10-CM category code for other abnormal findings of blood chemistry, so it cannot be submitted on claims. Use a more specific code from this category instead, such as R79.0, R79.1, R79.81, and R79.82. 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
R79
Billable Status
No — Non-Billable Category
Code Describes
Other abnormal findings of blood chemistry
Short Description
Other abnormal findings of blood chemistry
Same as the full description in the CMS dataset.
Chapter
R70-R79
Abnormal findings on examination of blood, without diagnosis

Code Classification

ChapterR00–R99Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified
SectionR70-R79Abnormal findings on examination of blood, without diagnosis
CategoryR79Other abnormal findings of blood chemistry
This CodeR79Other abnormal findings of blood chemistry

Specific Coding for Other abnormal findings of blood chemistryOverview

Non-specific codes like R79 require more characters. Use one of these billable codes instead:

  • Use R79.0 for Abnormal level of blood mineral

  • Use R79.1 for Abnormal coagulation profile

  • R79.8 for Other specified abnormal findings of blood chemistry

  • Use R79.81 for Abnormal blood-gas level

  • Use R79.82 for Elevated C-reactive protein (CRP)

  • Use R79.83 for Abnormal findings of blood amino-acid level

  • Use R79.89 for Other specified abnormal findings of blood chemistry

  • Use R79.9 for Abnormal finding of blood chemistry, unspecified

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to R79: its own notes plus those printed at block R70-R79 and Chapter 18. A note printed at a category, block or chapter applies to every code under it.

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

  • asymptomatic hyperuricemia (E79.0)
  • hypoglycemia NOS (E16.2)
  • neonatal hypoglycemia (P70.3-P70.4)
  • specific findings indicating disorder of amino-acid metabolism (E70-E72)
  • specific findings indicating disorder of carbohydrate metabolism (E73-E74)
  • specific findings indicating disorder of lipid metabolism (E75.-)

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

On R79 itself
  • hyperglycemia NOS (R73.9)
From Block R70-R79 Abnormal findings on examination of blood, without diagnosis applies to 45 codes
  • abnormal findings on antenatal screening of mother (O28.-)
  • abnormalities of lipids (E78.-)
  • abnormalities of platelets and thrombocytes (D69.-)
  • abnormalities of white blood cells classified elsewhere (D70-D72)
  • coagulation hemorrhagic disorders (D65-D68)
  • diagnostic abnormal findings classified elsewhere - see Alphabetical Index
  • hemorrhagic and hematological disorders of newborn (P50-P61)
From Chapter 18 (R00-R99) Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified applies to 774 codes
  • 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)

Use Additional Code

Add a second code, after this one, to fully describe the condition.

  • code to identify any retained foreign body, if applicable (Z18.-)

Notes

General instructions on how these codes are used.

From Chapter 18 (R00-R99) Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified applies to 774 codes
  • 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.

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name R79, its category, or a range that includes it.

Excludes2 1

These codes carry an Excludes2 note naming R79: its condition is not part of those codes, and both may be reported when the patient has both.

  • Block 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) names R70-R79, which includes this code

Patient EducationClinical

Blood

Your blood is made up of liquid and solids. The liquid part, called plasma, is made of water, salts, and protein. Over half of your blood is plasma. The solid part of your blood contains red blood cells, white blood cells, and platelets.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About R79Overview

What is the ICD-10 code for other abnormal findings of blood chemistry?

R79 is the ICD-10-CM category for other abnormal findings of blood chemistry, but it is a non-billable header: claims need a more specific code from this category, listed on this page.

Is R79 (Other abnormal findings of blood chemistry) a billable code?

No. This is a category header that groups the codes for other abnormal findings of blood chemistry, and headers cannot be submitted on claims. Claims for other abnormal findings of blood chemistry need a more specific code from this category, such as R79.0, R79.1, and R79.81.

Can R79 be a principal diagnosis?

Use it with care. This is a symptom code, so once a definitive diagnosis explaining the other abnormal findings of blood chemistry is established, that condition takes the principal position instead.

Can R79 be reported with E79.0?

Not as a rule. The Excludes1 note on R79 lists "asymptomatic hyperuricemia (E79.0)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).

Does R79 need an additional code?

When the condition applies, yes. The Use Additional Code note reads: code to identify any retained foreign body, if applicable (Z18.-). The additional code is reported after R79.