Q18.0
Sinus, fistula and cyst of branchial cleft
Billable FY2026 2025-10-01 → 2026-09-30
Exclusions 14 never code together
Q18code
Excludes1
- cleft lip and cleft palate (Q35-Q37)Q35-Q37
- conditions classified to Q67.0-Q67.4Q67.0-Q67.4
- congenital malformations of skull and face bones (Q75.-)Q75.-
- cyclopia (Q87.0)Q87.0
- dentofacial anomalies [including malocclusion] (M26.-)M26.-
- malformation syndromes affecting facial appearance (Q87.0)Q87.0
- persistent thyroglossal duct (Q89.2)Q89.2
Q10-Q18block
Excludes2
- cleft lip and cleft palate (Q35-Q37)Q35-Q37
- congenital malformation of cervical spine (Q05.0, Q05.5, Q67.5, Q76.0-Q76.4)Q05.0Q05.5Q67.5Q76.0-Q76.4
- congenital malformation of larynx (Q31.-)Q31.-
- congenital malformation of lip NEC (Q38.0)Q38.0
- congenital malformation of nose (Q30.-)Q30.-
- congenital malformation of parathyroid gland (Q89.2)Q89.2
- congenital malformation of thyroid gland (Q89.2)Q89.2
Excludes1 — never code together. The excluded condition and this one are mutually exclusive.
Excludes2 — not included here, but the patient may have both. Code both when documented.
Instructional notes 1
Q18.0code
Inclusion terms
- Branchial vestige
Index entries leading here 9
- Vestige, vestigial — see also Persistence
- branchial Q18.0
- Cyst (colloid) (mucous) (simple) (retention)
- Fistula (cutaneous) L98.8
- Sinus — see also Fistula
- branchial cleft (internal) (external) Q18.0
- Persistence, persistent (congenital)
- Imperfect
- Infection, infected, infective (opportunistic) B99.9
- branchial cyst Q18.0
- Cleft (congenital) — see also Imperfect, closure
- Branchiogenic remnant (in neck) Q18.0
Alongside this code 9 same parent — Q18
Additional references
AHA Coding Clinic® Licence required
Official coding advice for this code. Published by the American Hospital Association. Not included in this installation.