Q18 vs Q89.2
Q18 and Q89.2 can never be reported together. ICD-10-CM declares them mutually exclusive with an Excludes1 note, meaning the two conditions cannot occur in the same patient — so exactly one of them is correct for any given encounter.
The official note, declared on Q18
persistent thyroglossal duct (Q89.2)
Q18
Other congenital malformations of face and neck
Not billable
- Chapter 17
- Congenital malformations, deformations, chromosomal abnormalities, and genetic disorders
- Section
- Q10-Q18
Q89.2
Congenital malformations of other endocrine glands
Billable
- Chapter 17
- Congenital malformations, deformations, chromosomal abnormalities, and genetic disorders
- Section
- Q80-Q89
Use when the record says
- Congenital malformation of parathyroid or thyroid gland
- Persistent thyroglossal duct
- Thyroglossal cyst
Indexed under
- Retrosternal thyroid (congenital)
- Thyrolingual duct, persistent
- Aberrant › endocrine gland NEC (congenital)
- Aberrant › parathyroid gland (congenital)
- Aberrant › pituitary gland (congenital)
Excludes1 is not always absolute: where two conditions covered by the note are genuinely unrelated, CMS guidance permits reporting both. Document the reasoning rather than assuming it. More on Excludes1 vs Excludes2 · FY2027