ICD-10-CM 2027
ICD-10 code for thymus gland hypoplasia
From the official ICD-10-CM alphabetic index entry “Hypoplasia, hypoplastic › thymus (gland)”. Page updated September 29, 2026.
About coding thymus gland hypoplasia
The ICD-10-CM code for thymus gland hypoplasia is Q89.2 (Congenital malformations of other endocrine glands). The official index lists 1 more specific code, so check the documentation for details such as type, cause, site or severity before settling on Q89.2.
Within Q89, choose Q89.2 (Congenital malformations of other endocrine glands) only when documentation doesn't support a more specific option: congenital absence and malformations of spleen (Q89.0), congenital malformations of adrenal gland (Q89.1), Situs inversus (Q89.3), conjoined twins (Q89.4), multiple congenital malformations, not elsewhere classified (Q89.7), other specified congenital malformations (Q89.8) and congenital malformation, unspecified (Q89.9).
Don't report Q89.2 together with the conditions in its Excludes1 note: congenital goiter (E03.0) and congenital hypothyroidism (E03.1).
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
More specific thymus gland hypoplasia codes (official index)
- with immunodeficiency D82.1 — Di George's syndrome
Don't confuse with (Excludes1 for Q89.2)
Common questions about thymus gland hypoplasia ICD-10 codes
What is the ICD-10 code for thymus gland hypoplasia?
- Q89.2 — Congenital malformations of other endocrine glands. More specific codes apply when the documentation supports them: D82.1.
Is Q89.2 billable?
- Yes. Q89.2 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can Q89.2 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict Q89.2 as a principal diagnosis.
Is Q89.2 a CC or MCC?
- No. Q89.2 is neither a CC nor an MCC under MS-DRG v44.0.