Q92.8
BillableOther specified trisomies and partial trisomies of autosomes
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is Q92.8 an HCC code?
No. Q92.8 is a billable ICD-10-CM code but does not map to any HCC category in V28, V24, ESRD, or RxHCC.
HCC Category Mapping
RAF weights shown are the community, non-dual, aged base weights from the CMS risk adjustment model file. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.
MEAT Criteria for Q92.8
For Q92.8to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically — it has to be re-documented and supported each calendar year.
- MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
- EEvaluate: test results, medication response, or physical findings reviewed by the provider
- AAssess: explicit mention in the assessment or plan with acknowledgment of status
- TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis
Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed Q92.8 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
Q92.8 is the ICD-10-CM diagnosis code for other specified trisomies and partial trisomies of autosomes. Other specified chromosomal conditions involving extra copies of whole or partial chromosomes that don't fit into the more specific trisomy categories. Q92.8 sits in the ICD-10-CM chapter for congenital malformations, deformations, chromosomal abnormalities, and genetic disorders (q00-qa0), within the section covering chromosomal abnormalities, not elsewhere classified (q90-q99).
Q92.8 is a billable ICD-10-CM code but does not map to a payment HCC under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can be reported on Medicare Advantage encounter data submissions but it does not contribute to a beneficiary's RAF score and therefore does not affect risk-adjusted payments to the plan.
This code maps to RxHCC 148 (Mild Intellectual Disabilities) with a RAF weight of 0.0 in the RxHCC model. While it doesn't contribute to risk adjustment scoring, it identifies patients who may require specialized medications for seizures, behavioral issues, or other complications associated with chromosomal abnormalities.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for Q92.8 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Use this code for trisomies or partial trisomies not classified elsewhere
- •Provide documentation of the specific chromosome(s) involved when possible
Clinical Significance
This code captures various trisomies and partial trisomies not specified elsewhere, representing chromosomal abnormalities with extra genetic material that can cause developmental delays, intellectual disabilities, and congenital anomalies. These conditions require comprehensive medical management and developmental support throughout the patient's life.
Documentation Requirements
- ✓Cytogenetic analysis showing trisomy or partial trisomy
- ✓Specific chromosome(s) involved when known
- ✓Clinical manifestations and abnormalities
- ✓Developmental assessment results
- ✓Associated congenital anomalies
- ✓Intellectual disability evaluation
- ✓Genetic counseling documentation
- ✓Specialist evaluations and recommendations
Commonly Confused Codes
- •Q90-Q91 — Specific trisomies like Down syndrome, trisomy 18, or 13 should use their specific codes
- •Q927 — Triploidy involves complete chromosome sets, not individual trisomies
- •Q929 — Use specific code Q928 when the trisomy type is known
- •Q9359 — Deletions are opposite of trisomies which involve extra material