Is ICD-10-CM code Q99 billable?

No, Q99 (Other chromosome abnormalities, not elsewhere classified) 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 Q99 belong to?

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

Q99Not billable, use a more specific code below

Other chromosome abnormalities, not elsewhere classified

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

10 billable codes under Q99: 5 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 Q99.

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 Q99

Q99 can't be used on a claim. Pick a billable code below; grey headings group them.

Q99 MS-DRGs

As the principal diagnosis, the billable codes under Q99 group to these 11 MS-DRGs (v44.0). Which one applies depends on procedures performed, secondary diagnoses (CC/MCC), and the patient's age and discharge status.

DRG 564 Other Musculoskeletal System and Connective Tissue Diagnoses with MCC (5 of 10 codes)
DRG 565 Other Musculoskeletal System and Connective Tissue Diagnoses with CC (5 of 10 codes)
DRG 566 Other Musculoskeletal System and Connective Tissue Diagnoses without CC/MCC (5 of 10 codes)
DRG 729 Other Male Reproductive System Diagnoses with CC/MCC (3 of 10 codes)
DRG 730 Other Male Reproductive System Diagnoses without CC/MCC (3 of 10 codes)
DRG 742 Uterine and Adnexa Procedures for Non-Malignancy with CC/MCC (3 of 10 codes)
DRG 743 Uterine and Adnexa Procedures for Non-Malignancy without CC/MCC (3 of 10 codes)
DRG 760 Menstrual and Other Female Reproductive System Disorders with CC/MCC (3 of 10 codes)
DRG 761 Menstrual and Other Female Reproductive System Disorders without CC/MCC (3 of 10 codes)
DRG 884 Organic Disturbances and Intellectual Disability (1 of 10 codes)
DRG 951 Other Factors Influencing Health Status (1 of 10 codes)

Other codes that refer to Q99

Notes on these codes point to Q99.

CH10 Excludes2: congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
CH11 Excludes2: congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
CH12 Excludes2: congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
CH13 Excludes2: congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
CH14 Excludes2: congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
CH16 Excludes2: congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
CH3 Excludes2: congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
CH6 Excludes2: congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
CH7 Excludes2: congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
CH8 Excludes2: congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
CH9 Excludes2: congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
D84.81 Code First: chromosomal abnormalities (Q90-Q99)
E25 Excludes1: chromosomal abnormalities (Q90-Q99)
O99.8 Includes: Conditions in D00-D48, H00-H95, M00-N99, and Q00-Q99
P04 Excludes2: congenital malformations (Q00-Q99)
Q50-Q56 Excludes1: syndromes associated with anomalies in the number and form of chromosomes (Q90-Q99)
Q56 Excludes1: pseudohermaphroditism with specified chromosomal anomaly (Q96-Q99)
Z15 Excludes1: chromosomal anomalies (Q90-Q99)
Z82.7 Includes: Conditions classifiable to Q00-Q99

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.