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ICD10BillableValid for clinical use

ICD-10 Code R79.81: Abnormal blood-gas level

R79.81 is a billable ICD-10 diagnosis code used to classify Abnormal blood-gas level in medical records and claims. You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records. ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99).

Reviewed by HealthAssure Clinical TeamUpdated 26 May 2026

What is this code?

ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99).

When is it used?

  • May be used when a clinician documents abnormal blood-gas level in a patient's medical record.
  • May appear in hospital records, claims, referrals, and clinical documentation.
  • This code can be used as a clinically usable diagnosis entry in standardized coding workflows.

What it does not mean

  • A code alone does not explain severity, treatment plan, or outcome.
  • A medical code should not be treated as a substitute for a doctor's diagnosis or advice.

Code hierarchy

chapter
18Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99)
block
R70-R79Abnormal findings on examination of blood, without diagnosis
category
R79Other abnormal findings of blood chemistry
category
R79.8Other specified abnormal findings of blood chemistry
currentR79.8

Where you may see this code

You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records.

Related specialists

General PhysicianHematologist

Coverage-related procedures and services

CPT 87428high
INFECTIOUS AGENT ANTIGEN DETECTION BY IMMUNOASSAY TECHNIQUE (EG, ENZYME IMMUNOASSAY [EIA], ENZYME-LINKED IMMUNOSORBENT ASSAY [ELISA], FLUORESCENCE IMMUNOASSAY [FIA], IMMUNOCHEMILUMINOMETRIC ASSAY [IMCA]), QUALITATIVE OR SEMIQUANTITATIVE; SEVERE ACUTE RESPIRATORY SYNDROME CORONAVIRUS (EG, SARS-COV, SARS-COV-2 [COVID-19]) AND INFLUENZA VIRUS TYPES A AND B
Source: CMS coverage guidance
CPT 87631high
INFECTIOUS AGENT DETECTION BY NUCLEIC ACID (DNA OR RNA); RESPIRATORY VIRUS (EG, ADENOVIRUS, INFLUENZA VIRUS, CORONAVIRUS, METAPNEUMOVIRUS, PARAINFLUENZA VIRUS, RESPIRATORY SYNCYTIAL VIRUS, RHINOVIRUS), INCLUDES MULTIPLEX REVERSE TRANSCRIPTION, WHEN PERFORMED, AND MULTIPLEX AMPLIFIED PROBE TECHNIQUE, MULTIPLE TYPES OR SUBTYPES, 3-5 TARGETS
Source: CMS coverage guidance
CPT 87636high
INFECTIOUS AGENT DETECTION BY NUCLEIC ACID (DNA OR RNA); SEVERE ACUTE RESPIRATORY SYNDROME CORONAVIRUS 2 (SARS-COV-2) (CORONAVIRUS DISEASE [COVID-19]) AND INFLUENZA VIRUS TYPES A AND B, MULTIPLEX AMPLIFIED PROBE TECHNIQUE
Source: CMS coverage guidance
CPT 87637high
INFECTIOUS AGENT DETECTION BY NUCLEIC ACID (DNA OR RNA); SEVERE ACUTE RESPIRATORY SYNDROME CORONAVIRUS 2 (SARS-COV-2) (CORONAVIRUS DISEASE [COVID-19]), INFLUENZA VIRUS TYPES A AND B, AND RESPIRATORY SYNCYTIAL VIRUS, MULTIPLEX AMPLIFIED PROBE TECHNIQUE
Source: CMS coverage guidance
CPT 94642high
AEROSOL INHALATION OF PENTAMIDINE FOR PNEUMOCYSTIS CARINII PNEUMONIA TREATMENT OR PROPHYLAXIS
Source: CMS coverage guidance
CPT 94728high
AIRWAY RESISTANCE BY OSCILLOMETRY
Source: CMS coverage guidance

Coding guidelines

Common synonyms

Abnormal blood-gas level

Frequently asked questions

Code details

CodeR79.81
SystemICD10
Display nameAbnormal blood-gas level
ChapterSymptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99)
BlockAbnormal findings on examination of blood, without diagnosis

Flags

BillableYes
Valid clinical useYes

Source

SourceICD-10
Version2026-annual
Releaseannual
Year2026

Index terms

Matched terms
Abnormal, abnormality, abnormalitiesAbnormal, abnormality, abnormalities

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from ICD-10. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.

ICD-10 Code R79.81 for Abnormal blood-gas level | HealthAssure