2026 ICD-10-CM Diagnosis Code R00.9Unspecified abnormalities of heart beat

ICD-10-CM Codes›R00–R99›R00-R09›R00

ICD-10-CM R00.9
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

R00.9 is a billable ICD-10-CM diagnosis code for unspecified abnormalities of heart beat. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 314 through 316. 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 cardiac rate. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Circulatory signs and symptoms.

This medical diagnosis code is frequently used in Cardiology medical specialties to designate conditions such abnormalities of heart rhythm.

Code Identity

ICD-10-CM Code
R00.9
Billable Status
Yes — Valid for Submission
Code Describes
Unspecified abnormalities of heart beat
Short Description
Unspecified abnormalities of heart beat
Same as the full description in the CMS dataset.
Parent Code
R00
Abnormalities of heart beat

Code Classification

ChapterR00–R99Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified
SectionR00-R09Symptoms and signs involving the circulatory and respiratory systems
CategoryR00Abnormalities of heart beat
This CodeR00.9Unspecified abnormalities of heart beat

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Abnormal cardiac rate
  • Abnormal heart beat
  • Abnormal pulse rate
  • Abnormal radial pulse
  • Alteration in heart rate
  • Finding of pulse rate
  • Finding of regularity of heart rhythm
  • Unable to achieve target heart rate

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
      • heart
        • rate
    • Heart beat
      • abnormality

Clinical ClassificationClinical

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

CCSR SYM012
Circulatory signs and symptoms
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Arrhythmia

An arrhythmia is a problem with the rate or rhythm of your heartbeat. Your heart beats too quickly, too slowly, or with an irregular pattern. Changes in the electrical signals that control your heartbeat cause arrhythmias.

The full article covers:

  • What is an arrhythmia?
  • What causes an arrhythmia?
  • What are the symptoms of an arrhythmia?
  • How is an arrhythmia diagnosed?
  • What are the treatments for an arrhythmia?
  • Can arrhythmias be prevented?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert R00.9 to ICD-9-CMHistory

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

ICD-9-CM
785.3 Abnorm heart sounds 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 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About R00.9Overview

Is R00.9 (Abnormalities of heart beat) a billable code?

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

What MS-DRG does R00.9 group to?

When unspecified abnormalities of heart beat is the principal diagnosis on an inpatient stay, it groups to MS-DRG 314, 315, 316, with relative weights from 0.6821 to 2.0852 depending on complications. Higher weights mean higher Medicare reimbursement.

Can R00.9 be a principal diagnosis?

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

What is the ICD-9 equivalent of R00.9?

Under the General Equivalence Mappings, unspecified abnormalities of heart beat converts to ICD-9-CM 785.3 (abnorm heart sounds NEC). 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.