2026 ICD-10-CM Diagnosis Code R76.9Abnormal immunological finding in serum, unspecified

ICD-10-CM Codes›R00–R99›R70-R79›R76

ICD-10-CM R76.9
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

R76.9 is a billable ICD-10-CM diagnosis code for abnormal immunological finding in serum, unspecified. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 814 through 816. 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 antibody studies abnormal. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Abnormal findings without diagnosis.

Code Identity

ICD-10-CM Code
R76.9
Billable Status
Yes — Valid for Submission
Code Describes
Abnormal immunological finding in serum, unspecified
Short Description
Abnormal immunological finding in serum, unspecified
Same as the full description in the CMS dataset.
Parent Code
R76
Other abnormal immunological findings in serum

Code Classification

ChapterR00–R99Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified
SectionR70-R79Abnormal findings on examination of blood, without diagnosis
CategoryR76Other abnormal immunological findings in serum
This CodeR76.9Abnormal immunological finding in serum, unspecified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Antibody studies abnormal
  • Immunoelectrophoresis outside reference range
  • Serology detected

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
      • immunological findings
        • in serum

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

Convert R76.9 to ICD-9-CMHistory

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

ICD-9-CM
795.79 Oth unspcf nspf imun fnd
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 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About R76.9Overview

Is R76.9 (Other abnormal immunological findings in serum) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report abnormal immunological finding in serum, unspecified on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does R76.9 group to?

When abnormal immunological finding in serum, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 814, 815, 816, with relative weights from 0.6320 to 2.1267 depending on complications. Higher weights mean higher Medicare reimbursement.

Can R76.9 be a principal diagnosis?

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

What is the ICD-9 equivalent of R76.9?

Under the General Equivalence Mappings, abnormal immunological finding in serum, unspecified converts to ICD-9-CM 795.79 (oth unspcf nspf imun fnd). The mapping is approximate, so confirm the match fits the documentation.

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.