Is ICD-10-CM code Q91 billable?

No, Q91 (Trisomy 18 and Trisomy 13) is a non-billable ICD-10-CM code. It must be coded to a more specific subcategory before it can be used for reimbursement.

What chapter does ICD-10-CM code Q91 belong to?

Q91 belongs to Chapter 17 of the ICD-10-CM tabular list: Q00–Q99 (Congenital Malformations, Deformations and Chromosomal Abnormalities).

Q91Not billable, use a more specific code below

Trisomy 18 and Trisomy 13

In Chromosomal abnormalities, not elsewhere classified (Q90-Q99), chapter 17: Congenital Malformations, Deformations and Chromosomal Abnormalities

8 billable codes under Q91: all are a CC; none map to an HCC.A CC or MCC (major CC) is a secondary diagnosis that raises the MS-DRG payment.

Instructional notes

Also applies, from Chromosomal abnormalities, not elsewhere classified (Q90-Q99)

These notes sit on Q90-Q99 and apply to every code under it, including Q91.

Excludes2: not included here, code separately if applicable

mitochondrial metabolic disorders (E88.4-)

Official coding guidelines

From the ICD-10-CM Official Guidelines for Coding and Reporting, FY 2027 (CMS and NCHS). Links open the PDF at the right page.

Assign Q00-QA1 codes for documented congenital anomalies or genetic disorders at any age, coding non-inherent manifestations separately and sequencing Z38 first on the birth admission.

Read Section I.C.17 (page 74)

All codes under Q91

Q91 can't be used on a claim. Pick a billable code below; grey headings group them.

Q91 MS-DRG

As the principal diagnosis, all 8 billable codes under Q91 group to MS-DRG 884 (v44.0).

DRG 884 Organic Disturbances and Intellectual Disability

Other codes that refer to Q91

Notes on these codes point to Q91.

Q92 Excludes1: trisomies of chromosomes 13, 18, 21 (Q90-Q91)

About the condition

Plain-language background from MedlinePlus (National Library of Medicine), not coding guidance.

Genetic Disorders

Genetic disorders are health conditions caused by changes (also called mutations or variants) in your genes. Genes are parts of DNA found in your cells that carry instructions for how your body grows, develops, and functions. Many genes tell your body how to make proteins, which are needed for your body to work properly.

Code history

Valid since FY2016, when ICD-10-CM took effect on October 1, 2015. No changes since.