2026 ICD-10-CM Diagnosis Code R06.5Mouth breathing
ICD-10-CM Codes›R00–R99›R00-R09›R06
- Billable — Valid for Submission
- Not Chronic
R06.5 is a billable ICD-10-CM diagnosis code for mouth breathing. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 154 through 156. 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 Respiratory signs and symptoms.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Chronic mouth breathing
- Finding of route of breathing
- Mouth breathing
- Mouth breathing with nasal obstruction
- Obligatory mouth breathing
- Xerostomia
- Xerostomia due to mouth breathing
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Type 2 Excludes
- dry mouth NOS R68.2
A type 2 excludes note represents "Not included here". An excludes2 note indicates that the condition excluded is not part of the condition represented by the code, but a patient may have both conditions at the same time. When an Excludes2 note appears under a code, it is acceptable to use both the code and the excluded code together, when appropriate.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
- Snuffles (non-syphilitic) - R06.5
External Cause of Injuries IndexGuidance
References for this code in the External Cause of Injuries Index.
- Breathing
- mouth
- Snuffles(non-syphilitic)
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Mouth Breathing
abnormal breathing through the mouth, usually associated with obstructive disorders of the nasal passages.Xerostomia
decreased salivary flow.
Patient EducationClinical
Breathing Problems
When you're short of breath, it's hard or uncomfortable for you to take in the oxygen your body needs. You may feel as if you're not getting enough air. Sometimes you can have mild breathing problems because of a stuffy nose or intense exercise. But shortness of breath can also be a sign of a serious disease.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert R06.5 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About R06.5Overview
Is R06.5 (Abnormalities of breathing) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report mouth breathing on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does R06.5 group to?
When mouth breathing is the principal diagnosis on an inpatient stay, it groups to MS-DRG 154, 155, 156, with relative weights from 0.6911 to 1.5635 depending on complications. Higher weights mean higher Medicare reimbursement.
Can R06.5 be a principal diagnosis?
Use it with care. This is a symptom code, so once a definitive diagnosis explaining the mouth breathing is established, that condition takes the principal position instead.
What is the ICD-9 equivalent of R06.5?
Under the General Equivalence Mappings, mouth breathing converts to ICD-9-CM 784.99 (head & neck symptoms 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.
