Q93.52
BillablePhelan-McDermid syndrome
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is Q93.52 an HCC code?
No. Q93.52 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 Q93.52
For Q93.52to 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 Q93.52 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
Q93.52 is the ICD-10-CM diagnosis code for phelan-mcdermid syndrome. Phelan-McDermid syndrome is a rare genetic disorder caused by deletion of chromosome 22q13, characterized by developmental delays, intellectual disability, autism spectrum features, and distinctive facial features. Q93.52 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).
Q93.52 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 affect risk adjustment scoring, it identifies patients with Phelan-McDermid syndrome who often require specialized medications for autism-related behaviors, seizures, and other associated medical conditions.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for Q93.52 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This is a microdeletion syndrome; document the specific genes involved if genetic testing results are available
- •Often associated with autism spectrum disorder and speech/language delays; code these conditions separately if documented
Clinical Significance
Phelan-McDermid syndrome is a rare genetic disorder caused by deletions or mutations affecting the SHANK3 gene on chromosome 22q13, resulting in intellectual disability, autism spectrum behaviors, and absent or delayed speech. This condition requires comprehensive developmental support, behavioral interventions, and monitoring for associated medical complications.
Documentation Requirements
- ✓Genetic testing showing 22q13 deletion or SHANK3 mutation
- ✓Intellectual disability or global developmental delay
- ✓Absent or severely delayed speech development
- ✓Autism spectrum behaviors documented
- ✓Hypotonia or muscle weakness
- ✓Associated medical conditions (renal, cardiac if present)
- ✓Behavioral assessment findings
- ✓Genetic counseling documentation
Use Additional Code
Commonly Confused Codes
- •Q9351 — Angelman syndrome has different genetic cause and behavioral phenotype
- •Q9381 — Velocardiofacial syndrome involves different deletion and features
- •Q9359 — Use specific Phelan-McDermid code when 22q13 deletion confirmed
- •F84.0 — Autism may be present but underlying genetic cause is key