ICD-10-CM 2027
ICD-10 code for organ anomaly
From the official ICD-10-CM alphabetic index entry “Anomaly, anomalous (congenital) (unspecified type) › organ”. Page updated September 29, 2026.
About coding organ anomaly
The ICD-10-CM code for organ anomaly is Q89.9 (Congenital malformation, unspecified). The official index lists 1 more specific code, so check the documentation for details such as type, cause, site or severity before settling on Q89.9.
Within Q89, choose Q89.9 (Congenital malformation, unspecified) 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), congenital malformations of other endocrine glands (Q89.2), Situs inversus (Q89.3), conjoined twins (Q89.4), multiple congenital malformations, not elsewhere classified (Q89.7) and other specified congenital malformations (Q89.8).
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
In MS-DRG v44.0, it is part of the grouping logic for DRG 951 (Other Factors Influencing Health Status, relative weight 0.5577), in MDC 23 (Factors Influencing Health Status and Other Contacts with Health Services), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
More specific organ anomaly codes (official index)
- of Corti Q16.5 — Congenital malformation of inner ear
Common questions about organ anomaly ICD-10 codes
What is the ICD-10 code for organ anomaly?
- Q89.9 — Congenital malformation, unspecified. More specific codes apply when the documentation supports them: Q16.5.
Is Q89.9 billable?
- Yes. Q89.9 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can Q89.9 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict Q89.9 as a principal diagnosis.
Is Q89.9 a CC or MCC?
- No. Q89.9 is neither a CC nor an MCC under MS-DRG v44.0.