Q99.9 Chromosomal abnormality, unspecified

Billable ICD-10-CM code, FY2026. Exempt from present-on-admission (POA) reporting.

MS-DRG index

Defines the logic of DRG(s) 951 in MDC 23.

Approximate ICD-9-CM (GEMs)

• 758.9 Conditions due to anomaly of unspecified chromosome

Code annotations containing back-references to Q99.9

Back-references to Q99

• Code First: D84.81 Immunodeficiency due to conditions classified elsewhere ("chromosomal abnormalities (Q90-Q99)")
• Type 1 Excludes: E25 Adrenogenital disorders ("chromosomal abnormalities (Q90-Q99)")
• Type 2 Excludes: P04 Newborn affected by noxious substances transmitted via placenta or breast milk ("congenital malformations (Q00-Q99)")
• Type 1 Excludes: Q56 Indeterminate sex and pseudohermaphroditism ("pseudohermaphroditism with specified chromosomal anomaly (Q96-Q99)")
• Type 1 Excludes: Z15 Genetic susceptibility to disease ("chromosomal anomalies (Q90-Q99)")

Diagnosis Index entries for Q99.9

• Abnormal, abnormality, abnormalities › autosomes
• Abnormal, abnormality, abnormalities › chromosome, chromosomal
• Anomaly, anomalous (congenital) (unspecified type) › chromosomes, chromosomal
• Syndrome › due to abnormality › chromosomal

Nearby codes

• Q99.812 Usher syndrome, type 2
• Q99.813 Usher syndrome, type 3
• Q99.818 Other Usher syndrome
• Q99.819 Usher syndrome, unspecified
• Q99.89 Other specified chromosome abnormalities
• Q99.9 Chromosomal abnormality, unspecified (this code)