2026 ICD-10-CM Diagnosis Code R79.83Abnormal findings of blood amino-acid level

ICD-10-CM CodesR00–R99R70-R79R79

ICD-10-CM R79.83
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

R79.83 is a billable ICD-10-CM diagnosis code for abnormal findings of blood amino-acid level. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) 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 amino acid below reference range. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Abnormal findings without diagnosis.

Code Identity

ICD-10-CM Code
R79.83
Billable Status
Yes — Valid for Submission
Code Describes
Abnormal findings of blood amino-acid level
Short Description
Abnormal findings of blood amino-acid level
Same as the full description in the CMS dataset.
Parent Code
Other specified 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 CodeR79.83Abnormal findings of blood amino-acid level

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Amino acid below reference range
  • Homocystinemia
  • Serum amino acid above reference range
  • Serum amino acid below reference range
  • Serum amino acid levels - finding
  • Serum amino acids outside reference range

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Homocysteinemia

Type 1 Excludes

  • disorders of amino-acid metabolism E70 E72

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Abnormal, abnormality, abnormalities
      • blood amino-acid level
    • Homocysteinemia
    • Homocystinemia

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

Code History & ChangesHistory

Replacement R79.83 replaces the following previously assigned code(s):

  • R79.89 - Other specified abnormal findings of blood chemistry
FY 2022AddedAdded to the ICD-10-CM code setEffective October 1, 2021.
FY 2023–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About R79.83Overview

Is R79.83 (Other specified abnormal findings of blood chemistry) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report abnormal findings of blood amino-acid level on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does R79.83 group to?

When abnormal findings of blood amino-acid level is the principal diagnosis on an inpatient stay, it groups to MS-DRG 947, 948, with relative weights from 0.8005 to 1.2694 depending on complications. Higher weights mean higher Medicare reimbursement.

Can R79.83 be a principal diagnosis?

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

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.