Q93.59
BillableOther deletions of part of a chromosome
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is Q93.59 an HCC code?
No. Q93.59 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 Q93.59
For Q93.59to 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 Q93.59 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
Q93.59 is the ICD-10-CM diagnosis code for other deletions of part of a chromosome. A chromosomal deletion affecting a portion of a chromosome other than those specified in codes Q93.3, Q93.4, Q93.51, or Q93.52, resulting in loss of genetic material and potential developmental or health effects. Q93.59 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).
Q93.59 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. Although it doesn't contribute to risk adjustment scoring, it identifies patients with chromosomal deletions who may require specialized medications for associated conditions like seizures, behavioral issues, or developmental delays.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for Q93.59 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Use this code for deletions of chromosome segments not captured by more specific codes; document which chromosome and which arm is affected
- •Specify the clinical manifestations and associated conditions to provide complete clinical documentation
Clinical Significance
This code encompasses various chromosomal deletions not specified in other categories, representing loss of genetic material that can cause developmental delays, intellectual disabilities, and congenital anomalies. The clinical significance varies depending on the size and location of the deletion and which genes are affected.
Documentation Requirements
- ✓Cytogenetic or molecular genetic testing showing deletion
- ✓Specific chromosome and region involved if known
- ✓Size of deletion if documented
- ✓Clinical manifestations in the affected individual
- ✓Developmental assessment results
- ✓Associated congenital anomalies
- ✓Intellectual disability evaluation
- ✓Genetic counseling provided