ICD-10 Q91.0
Billable / Specific CCTrisomy 18, nonmosaicism (meiotic nondisjunction)
About ICD-10-CM Q91.0
ICD-10-CM code Q91.0 represents Trisomy 18, nonmosaicism (meiotic nondisjunction). This is a billable/specific code in the Congenital Malformations chapter (block Q91). The 2026 edition of ICD-10-CM Q91.0 became effective on October 1, 2025.
Coding Tips for Q91.0
Specialist guidance from the PayerReady Medical Coding Team. Specificity warnings, HCC capture rules, sequencing notes.
Q91.0 is designated CC for MS-DRG grouping. On inpatient claims, this code can shift the DRG to the with-CC variant when documented as a present-on-admission secondary diagnosis. Hospital CDI programs flag CC opportunities during chart review. Failure to capture this code may leave 30 to 80 percent of the inpatient stay revenue unrealized.
Inpatient DRG Impact, CC
codes Trisomy 18, nonmosaicism (meiotic nondisjunction). As a Complication/Comorbidity (CC), this contributes to DRG severity adjustment when documented alongside the principal diagnosis.
Medicare LCD Coverage for Q91.0
Local Coverage Determinations (LCDs) from CMS MACs that list Q91.0 as a covered diagnosis.
Showing top 10 of 91 total . Click a CPT for full coverage scope.
Commercial Payer Coverage
Coverage policies from major commercial payers referencing Q91.0.
3 Medicare
2 Aetna
CPT Codes Commonly Billed with Q91.0
Procedures frequently paired with this diagnosis based on PayerReady's Dx↔Px linkage data.
We don't have CPT pairings indexed for this specific code yet. Use the CPT search above to find common procedures, or check your payer's published medical policy for code-specific guidance.
Convert Q91.0 to ICD-9-CM
Per CMS General Equivalence Mappings (GEMs), useful for legacy data review and historical claim analysis.
| ICD-10 | ICD-9 | Mapping Flags |
|---|---|---|
| Q91.0 | 7582 | 10000 |
Flags format (5 digits): Approximate · No Map · Combination · Scenario · Choice List. Source: CMS 2017 GEMs (final version).
Codes Adjacent To Q91.0
Other codes in section Q90-Q99 (Chromosomal abnormalities, not elsewhere classified).
ICD-10 Q91.0, Billing FAQ
Is ICD-10 code Q91.0 billable? +
Yes, Q91.0 is a billable ICD-10-CM code that can appear as a primary or secondary diagnosis on claims.
Is Q91.0 a CC or MCC for inpatient DRG? +
Yes, this code is designated as CC. Documenting as a secondary diagnosis on inpatient claims can shift the DRG to a higher-weighted category.
What ICD-9 codes does Q91.0 map to? +
Per CMS GEMs, Q91.0 maps to ICD-9 codes: 7582. Useful for legacy data review and historical claim analysis.
Get the full PayerReady toolkit
Free access to CPT/ICD-10 lookup, denial appeals, fee comparator, and claim auditing with credentialing enrollment.
Start free →Run this code through our claim audit tool
Check NCCI bundling, MUE limits, and modifier logic before submission.
Try the auditor →Did this page help?
Quick signal so we know what to improve.
If you want a code reference page that doesn't exist yet, email coding@payerready.com.
Tell us what's missing or wrong: coding@payerready.com. We respond within 5 business days.
Reviewed by the PayerReady Medical Coding Team
Verified against the CMS 2026 code set on May 31, 2026.
Powered by 11K CPT · 98K ICD-10 · 860K MPFS rates · 4.5M NCCI edits · 9.5M NPIs. Our data methodology · About our coding team