Q93.88
BillableOther microdeletions
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is Q93.88 an HCC code?
No. Q93.88 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 Q93.88
For Q93.88to 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 Q93.88 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
Q93.88 is the ICD-10-CM diagnosis code for other microdeletions. A microdeletion (loss of a small segment of DNA) on a chromosome other than those specified in codes Q93.51, Q93.52, Q93.81, or Q93.82, which can cause various developmental, intellectual, or physical abnormalities depending on the genes involved. Q93.88 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).
Q93.88 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 with microdeletion syndromes who may require specialized medications for associated conditions like seizures, behavioral issues, or other complications.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for Q93.88 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Specify which chromosome and which region contains the microdeletion; genetic testing reports should be referenced
- •Microdeletions can have variable clinical presentations; document all identified clinical manifestations and associated conditions
Clinical Significance
This code encompasses various microdeletions not specified elsewhere, representing small deletions of chromosomal material that can cause significant developmental abnormalities and intellectual disabilities despite their small size. The clinical impact depends on which genes are deleted and their functional importance.
Documentation Requirements
- ✓Molecular genetic testing showing microdeletion
- ✓Specific chromosome region involved
- ✓Size of deletion if documented
- ✓Genes involved if known
- ✓Clinical manifestations in affected individual
- ✓Developmental assessment results
- ✓Associated congenital anomalies
- ✓Genetic counseling provided
Commonly Confused Codes
- •Q9351-Q9352 — Use specific codes for Angelman or Phelan-McDermid syndromes
- •Q9381-Q9382 — Use specific codes for velocardiofacial or Williams syndromes
- •Q9359 — Larger deletions vs. microdeletions
- •Q939 — Use specific microdeletion code when confirmed