Q18.0 Sinus, fistula and cyst of branchial cleft

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

Applicable to

• Branchial vestige

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) 154-156 in MDC 03.

Approximate ICD-9-CM (GEMs)

• 744.41 Branchial cleft sinus or fistula (approximate)
• 744.42 Branchial cleft cyst (approximate)

Code annotations containing back-references to Q18.0

Back-references to Q18.0

• Type 1 Excludes: H70.8 Other mastoiditis and related conditions ("sinus, fistula, and cyst of branchial cleft (Q18.0)")

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 Q18.0

• Branchiogenic remnant (in neck)
• Cleft (congenital) › branchial (persistent) › cyst
• Cleft (congenital) › branchial (persistent) › cyst › fistula
• Cleft (congenital) › branchial (persistent) › cyst › sinus
• Cyst (colloid) (mucous) (simple) (retention) › branchial (cleft)
• Cyst (colloid) (mucous) (simple) (retention) › branchiogenic
• Cyst (colloid) (mucous) (simple) (retention) › cervical lateral
• Fistula (cutaneous) › branchial (cleft)
• Fistula (cutaneous) › branchiogenous
• Fistula (cutaneous) › pharynx › branchial cleft (congenital)
• Imperfect › closure (congenital) › branchial cleft NOS › cyst
• Imperfect › closure (congenital) › branchial cleft NOS › fistula
• Imperfect › closure (congenital) › branchial cleft NOS › sinus
• Infection, infected, infective (opportunistic) › branchial cyst
• Persistence, persistent (congenital) › branchial cleft NOS › cyst
• Persistence, persistent (congenital) › branchial cleft NOS › fistula
• Persistence, persistent (congenital) › branchial cleft NOS › sinus
• Sinus › branchial cleft (internal) (external)
• Vestige, vestigial › branchial

Nearby codes

• Q18 Other congenital malformations of face and neck
• Q18.0 Sinus, fistula and cyst of branchial cleft (this code)
• Q18.1 Preauricular sinus and cyst
• Q18.2 Other branchial cleft malformations
• Q18.3 Webbing of neck
• Q18.4 Macrostomia
• Q18.5 Microstomia