2026 ICD-10-CM Diagnosis Code R77.9Abnormality of plasma protein, unspecified

ICD-10-CM Codes›R00–R99›R70-R79›R77

ICD-10-CM R77.9
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

R77.9 is a billable ICD-10-CM diagnosis code for abnormality of plasma protein, unspecified. 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 lipoprotein electrophoresis outside reference range. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Abnormal findings without diagnosis.

Code Identity

ICD-10-CM Code
R77.9
Billable Status
Yes — Valid for Submission
Code Describes
Abnormality of plasma protein, unspecified
Short Description
Abnormality of plasma protein, unspecified
Same as the full description in the CMS dataset.
Parent Code
R77
Other abnormalities of plasma proteins

Code Classification

ChapterR00–R99Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified
SectionR70-R79Abnormal findings on examination of blood, without diagnosis
CategoryR77Other abnormalities of plasma proteins
This CodeR77.9Abnormality of plasma protein, unspecified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Lipoprotein electrophoresis outside reference range
  • Plasma protein above reference range
  • Plasma proteins below reference range
  • Serum protein above reference range

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
      • plasma
        • protein
    • Proteinemia

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 R77.9 to ICD-9-CMHistory

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

ICD-9-CM
790.99 Oth nspcf finding blood
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 R77.9Overview

Is R77.9 (Other abnormalities of plasma proteins) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report abnormality of plasma protein, unspecified on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does R77.9 group to?

When abnormality of plasma protein, unspecified 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 R77.9 be a principal diagnosis?

Use it with care. This is a symptom code, so once a definitive diagnosis explaining the abnormality of plasma protein, unspecified is established, that condition takes the principal position instead.

What is the ICD-9 equivalent of R77.9?

Under the General Equivalence Mappings, abnormality of plasma protein, unspecified converts to ICD-9-CM 790.99 (oth nspcf finding blood). 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.