Q91
Non-Billable

Trisomy 18 and Trisomy 13

Non-Billable / Non-Specific Code

What is Trisomy 18 and Trisomy 13?

ICD-10-CM Q91 is the diagnosis code for Trisomy 18 and Trisomy 13. This code falls under the section "Chromosomal abnormalities, not elsewhere classified" within Chapter 17 — Congenital malformations, deformations and chromosomal abnormalities (Q00-QA0). It is a non-billable/non-specific ICD-10-CM code that should not be used for reimbursement. A more specific sub-code is required for billing. Medical coders and healthcare providers use this code to document and classify diagnoses in electronic health records, insurance claims, and clinical databases.

Coding Guidelines for Q91

Always refer to the official ICD-10-CM Tabular List for complete coding guidelines. Ensure documentation supports the specificity of the code selected. When in doubt, consult a certified medical coder or the latest CMS guidelines.

ICD-10-CM Code Hierarchy

Understanding where Q91 sits in the ICD-10-CM classification helps ensure proper coding:

Sub-Codes 8 entries
Q91.0Trisomy 18, nonmosaicism (meiotic nondisjunction)BillableQ91.1Trisomy 18, mosaicism (mitotic nondisjunction)BillableQ91.2Trisomy 18, translocationBillableQ91.3Trisomy 18, unspecifiedBillableQ91.4Trisomy 13, nonmosaicism (meiotic nondisjunction)BillableQ91.5Trisomy 13, mosaicism (mitotic nondisjunction)BillableQ91.6Trisomy 13, translocationBillableQ91.7Trisomy 13, unspecifiedBillable
Related Codes

Frequently Asked Questions

Is Q91 a billable ICD-10-CM code?

No, Q91 is a non-billable/non-specific code. You should use a more specific sub-code for billing and reimbursement.

What does Q91 mean?

Q91 is the ICD-10-CM diagnosis code for "Trisomy 18 and Trisomy 13". It is used by healthcare providers to classify and document this condition in medical records and insurance claims.

What section is Q91 in?

Q91 is located in Section Q90-Q99 — "Chromosomal abnormalities, not elsewhere classified" within Chapter 17 of the ICD-10-CM Tabular List.

What are the sub-codes of Q91?

Q91 has 8 sub-code(s) that provide more specific detail: Q91.0, Q91.1, Q91.2, Q91.3, Q91.4 and more.

When should I use Q91?

Use Q91 when the patients documented diagnosis matches "Trisomy 18 and Trisomy 13" and the clinical documentation supports this level of specificity. Always verify with the latest ICD-10-CM guidelines and payer requirements.

People Also Ask

What is the ICD-10 code for Trisomy 18 and Trisomy 13?

The ICD-10-CM code for Trisomy 18 and Trisomy 13 is Q91.

Can Q91 be used for primary diagnosis?

No, Q91 is non-billable. Use a more specific sub-code for primary diagnosis billing.

What chapter is Q91 in?

Q91 is in Chapter 17 of the ICD-10-CM Tabular List.

Is Q91 valid for 2026?

Yes, Q91 is a valid ICD-10-CM code for the 2026 fiscal year, subject to official CMS updates.

See Also

← PreviousQ90.9Down syndrome, unspecifiedNext →Q91.0Trisomy 18, nonmosaicism (meiotic nondisjunction)
Code Details
Q91
Trisomy 18 and Trisomy 13
Non-Billable / Non-Specific Code
17 — Congenital malformations, deformations and chromosomal abnormalities (Q00-QA0)
Q90-Q99 — Chromosomal abnormalities, not elsewhere classified
2026 ICD-10-CM