ICD-10-CM 2027
ICD-10 code for mouth breathing
From the official ICD-10-CM alphabetic index entry “Breathing › mouth”. Page updated September 29, 2026.
About coding mouth breathing
The ICD-10-CM code for mouth breathing is R06.5 (Mouth breathing). The official index lists 1 more specific code, so check the documentation for details such as type, cause, site or severity before settling on R06.5.
Within R06 (abnormalities of breathing), R06.5 is specifically for mouth breathing. Related codes cover dyspnea (R06.0), Stridor (R06.1), Wheezing (R06.2), periodic breathing (R06.3), Hyperventilation (R06.4), Hiccough (R06.6), Sneezing (R06.7), other abnormalities of breathing (R06.8) and 1 more.
The conditions in its Excludes2 note aren't part of R06.5, but may be coded alongside it if the patient has both: dry mouth NOS (R68.2).
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
More specific mouth breathing codes (official index)
- causing malocclusion M26.59 — Other dentofacial functional abnormalities
Common questions about mouth breathing ICD-10 codes
What is the ICD-10 code for mouth breathing?
- R06.5 — Mouth breathing. More specific codes apply when the documentation supports them: M26.59.
What is the ICD-10 code for causing malocclusion mouth breathing?
- M26.59 — Other dentofacial functional abnormalities.
Is R06.5 billable?
- Yes. R06.5 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can R06.5 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict R06.5 as a principal diagnosis.
Is R06.5 a CC or MCC?
- No. R06.5 is neither a CC nor an MCC under MS-DRG v44.0.