2026 ICD-10-CM Diagnosis Code R70.1Abnormal plasma viscosity

ICD-10-CM Codes›R00–R99›R70-R79›R70

ICD-10-CM R70.1
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

R70.1 is a billable ICD-10-CM diagnosis code for abnormal plasma viscosity. 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. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Abnormal findings without diagnosis.

Code Identity

ICD-10-CM Code
R70.1
Billable Status
Yes — Valid for Submission
Code Describes
Abnormal plasma viscosity
Short Description
Abnormal plasma viscosity
Same as the full description in the CMS dataset.
Parent Code
R70
Elevated erythrocyte sedimentation rate and abnormality of plasma viscosity

Code Classification

ChapterR00–R99Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified
SectionR70-R79Abnormal findings on examination of blood, without diagnosis
CategoryR70Elevated erythrocyte sedimentation rate and abnormality of plasma viscosity
This CodeR70.1Abnormal plasma viscosity

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Blood viscosity above reference range
  • Blood viscosity below reference range
  • Blood viscosity level - finding
  • Hyperviscosity
  • Hypoviscosity
  • Plasma viscosity - finding
  • Plasma viscosity above reference range
  • Plasma viscosity below reference range
  • Plasma viscosity outside reference range
  • Reticulocyte count outside reference range
  • Reticulocytosis
  • Reticulocytosis after B12

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
        • viscosity
    • Reticulocytosis

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

Clinical InformationClinical

  • Reticulocytosis

    an increase in circulating reticulocytes, which is among the simplest and most reliable signs of accelerated erythrocyte production. reticulocytosis occurs during active blood regeneration (stimulation of red bone marrow) and in certain types of anemia, particularly congenital hemolytic anemia.

  • Reticulocytosis

    a laboratory test result indicating an increased number of reticulocytes in the peripheral blood.

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 R70.1 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 R70.1Overview

Is R70.1 a billable code?

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

What MS-DRG does R70.1 group to?

When abnormal plasma viscosity 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 R70.1 be a principal diagnosis?

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

What is the ICD-9 equivalent of R70.1?

Under the General Equivalence Mappings, abnormal plasma viscosity 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.