Q18.5
BillableMicrostomia
Microstomia
Coding Notes
Excludes 1
Codes that cannot be used together with this code (mutual exclusion)
Excludes 2
Conditions not included here, but the patient may have both
- •inborn errors of metabolismE70-E88
- •cleft lip and cleft palateQ35-Q37
- •congenital malformation of cervical spine, , ,Q05.0, Q05.5, Q67.5, Q76.0-Q76.4
- •congenital malformation of larynxQ31
- •congenital malformation of lip NECQ38.0
- •congenital malformation of noseQ30
- •congenital malformation of parathyroid glandQ89.2
- •congenital malformation of thyroid glandQ89.2
Related Codes(9)
Q18.0Sinus, fistula and cyst of branchial cleft
Q18.1Preauricular sinus and cyst
Q18.2Other branchial cleft malformations
Q18.3Webbing of neck
Q18.4Macrostomia
Q18.6Macrocheilia
Q18.7Microcheilia
Q18.8Other specified congenital malformations of face and neck
Q18.9Congenital malformation of face and neck, unspecified
ICD-11 Equivalents(1)
ICD-11 Equivalents
View full mappingCorresponding ICD-11 codes from the WHO crosswalk mapping
Also Known As / Clinical Terms(20)
SNOMED CT
UMLS
Clinical Terms
- Microstomias
- Blepharophimosis, telecanthus, microstomia syndrome
- Narrow mouth
- Simosa Penchaszadeh Bustos syndrome
- Small mouth
- Small oral aperture
- Flat face, microstomia, ear anomaly syndrome
- Simosa craniofacial syndrome
- Microstomia (disorder)
Frequently Asked Questions
What is the ICD-10 code for microstomia?
The ICD-10-CM code for microstomia is Q18.5. The full clinical description is "Microstomia". Q18.5 is a billable/specific code that can be used on insurance claims and medical billing.
What does ICD-10 code Q18.5 mean?
ICD-10-CM code Q18.5 represents “Microstomia”. It is classified under Chapter 17: Congenital Malformations, Deformations and Chromosomal Abnormalities and is a billable/specific code that can be used on a claim.
Is Q18.5 a billable code?
Yes, Q18.5 is a billable/specific ICD-10-CM code and can be used to indicate a diagnosis on a medical claim.
What chapter is Q18.5 in?
Q18.5 is in Chapter 17: Congenital Malformations, Deformations and Chromosomal Abnormalities (codes Q00-Q99).
What codes cannot be used with Q18.5?
Q18.5 has Excludes1 notes indicating codes that cannot be used together with it, including: cleft lip and cleft palate (Q35-Q37); conditions classified to Q67.0-Q67.4; congenital malformations of skull and face bones (Q75.-); and 4 more.
What SNOMED CT codes does Q18.5 map to?
Q18.5 maps to 2 SNOMED CT concepts: 773750003, 14582003. SNOMED CT is a clinical terminology used in electronic health records.
What are the UMLS CUIs for Q18.5?
Q18.5 is linked to 1 UMLS Concept Unique Identifier: C0026034. The UMLS (Unified Medical Language System) integrates multiple biomedical vocabularies maintained by the U.S. National Library of Medicine.
How does Q18.5 relate to ICF functioning codes?
ICF (International Classification of Functioning, Disability and Health) codes describe how conditions like microstomia affect a person's functioning — body functions, activities, participation, and environmental factors. AutoICD provides ICF Core Sets for 12+ conditions and can map clinical text to ICF categories automatically. Browse the ICF directory to explore functioning codes.
What is the ICD-11 equivalent of Q18.5?
Q18.5 maps to the ICD-11 code: LA31.4 (Microstomia).
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Includes SNOMED Clinical Terms® (SNOMED CT®) used by permission of SNOMED International. Includes content from the UMLS Metathesaurus, courtesy of the U.S. National Library of Medicine.