2027 ICD-10-CM Diagnosis Code R79.9Abnormal finding of blood chemistry, unspecified

ICD-10-CM Codes›R00–R99›R70-R79›R79

ICD-10-CM R79.9
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

R79.9 is a billable ICD-10-CM diagnosis code for abnormal finding of blood chemistry, unspecified. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 947 through 948. As a symptom code, it should not be used as a principal diagnosis once a related definitive diagnosis has been established. Coders also document this condition as abnormal blood test. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Abnormal findings without diagnosis.

Code Identity

ICD-10-CM Code
R79.9
Billable Status
Yes — Valid for Submission
Code Describes
Abnormal finding of blood chemistry, unspecified
Short Description
Abnormal finding of blood chemistry, unspecified
Same as the full description in the CMS dataset.
Parent Code
R79
Other abnormal findings of blood chemistry

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 CodeR79.9Abnormal finding of blood chemistry, unspecified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Abnormal blood test
  • Blood chemistry outside reference range
  • Blood substance level above reference range
  • Blood substance level below reference range
  • Finding of vitamin B12 level
  • Full blood count outside reference range
  • Hematology test outside reference range
  • Serum chloride level outside reference range
  • Serum electrolyte levels - finding
  • Vitamin B12 level below reference range

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to R79.9: its own notes plus those printed at R79, 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.

From R79 Other abnormal findings of blood chemistry applies to 7 codes
  • 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.

From R79 Other abnormal findings of blood chemistry applies to 7 codes
  • 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.

From R79 Other abnormal findings of blood chemistry applies to 7 codes
  • 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 R79.9, its category, or a range that includes it.

Excludes2 1

These codes carry an Excludes2 note naming R79.9: 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

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR SYM017
Abnormal findings without diagnosis
Default principal diagnosis: inpatient Yes · outpatient Yes

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.

Convert R79.9 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
790.6 Abn blood chemistry NEC
Approximate The match is approximate rather than exact.

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 R79.9Overview

What is the ICD-10 code for abnormal finding of blood chemistry, unspecified?

The ICD-10-CM code for abnormal finding of blood chemistry, unspecified is R79.9 (sometimes written as R799). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is R79.9 (Other abnormal findings of blood chemistry) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report abnormal finding of blood chemistry, unspecified on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does R79.9 group to?

When abnormal finding of blood chemistry, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 948, 947, with relative weights from 0.7833 to 1.2608 depending on complications. Higher weights mean higher Medicare reimbursement.

Can R79.9 be a principal diagnosis?

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

Can R79.9 be reported with E79.0?

Not as a rule. The Excludes1 note at R79, which applies to R79.9, 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).