Q18.5 Microstomia

Billable ICD-10-CM code, FY2026. Exempt from present-on-admission (POA) reporting.

Applies from Q18 Other congenital malformations of face and neck

Excludes1 (never code together)

• cleft lip and cleft palate (Q35-Q37)
• conditions classified to Q67.0-Q67.4
• congenital malformations of skull and face bones (Q75.-)
• cyclopia (Q87.0)
• dentofacial anomalies [including malocclusion] (M26.-)
• malformation syndromes affecting facial appearance (Q87.0)
• persistent thyroglossal duct (Q89.2)

MS-DRG index

Defines the logic of DRG(s) 157-159 in MDC 03.

Approximate ICD-9-CM (GEMs)

• 744.84 Microstomia

Code annotations containing back-references to Q18.5

Back-references to Q18.5

• Type 1 Excludes: Q38 Other congenital malformations of tongue, mouth and pharynx ("microstomia (Q18.5)")

Back-references to Q18

• Type 1 Excludes: Q75 Other congenital malformations of skull and face bones ("congenital malformation of face NOS (Q18.-)")

Diagnosis Index entries for Q18.5

• Microstomia (congenital)

Nearby codes

• Q18.0 Sinus, fistula and cyst of branchial cleft
• Q18.1 Preauricular sinus and cyst
• Q18.2 Other branchial cleft malformations
• Q18.3 Webbing of neck
• Q18.4 Macrostomia
• Q18.5 Microstomia (this code)
• Q18.6 Macrocheilia
• Q18.7 Microcheilia
• Q18.8 Other specified congenital malformations of face and neck
• Q18.9 Congenital malformation of face and neck, unspecified