Q18.1 Preauricular sinus and cyst

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Instructional notes

Chapter 17

Excludes2Not included here: the patient may have both; report both when both are present.

inborn errors of metabolism (E70-E88)

Notes

Codes from this chapter are not for use on maternal records

Section Q10-Q18

Excludes2Not included here: the patient may have both; report both when both are present.

cleft lip and cleft palate (Q35-Q37)
congenital malformation of cervical spine (Q05.0, Q05.5, Q67.5, Q76.0-Q76.4)
congenital malformation of larynx (Q31.-)
congenital malformation of lip NEC (Q38.0)
congenital malformation of nose (Q30.-)
congenital malformation of parathyroid gland (Q89.2)
congenital malformation of thyroid gland (Q89.2)

Q18

Excludes1Not coded here: never report with this code, except when the two conditions are unrelated.

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)

This code

Inclusion terms

Fistula of auricle, congenital
Cervicoaural fistula

Chapter 17: Congenital malformations, deformations, chromosomal abnormalities, and genetic disorders (Q00-QA1) · Q10-Q18 Congenital malformations of eye, ear, face and neck (Q10-Q18)

Source: ICD-10-CM FY 2027 code descriptions and tabular list (CMS and CDC National Center for Health Statistics), effective 2026-10-01 through 2027-09-30 · CMS ICD-10 files. HCC mapping: CMS-HCC V28, payment year 2027. As of 2026-11-04.

Coverage and payment depend on the claim details; confirm with the Medicare Administrative Contractor.