F79
BillableUnspecified intellectual disabilities
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is F79 an HCC code?
No. F79 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 F79
For F79to 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 F79 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
F79 is the ICD-10-CM diagnosis code for unspecified intellectual disabilities. Intellectual disability where the specific cause or severity level cannot be determined or is not documented. This is a catch-all code for intellectual disabilities that don't meet criteria for more specific diagnoses. F79 sits in the ICD-10-CM chapter for mental, behavioral and neurodevelopmental disorders (f01-f99), within the section covering intellectual disabilities (f70-f79).
F79 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.
F79 does not map to any HCC in V28 or V24 models. RxHCC maps to RxHCC 148 (0.000 weight). No direct RAF score impact. Always pursue severity specification for better clinical documentation. Coders reviewing F79 should check whether additional documentation would support a more specific child code in the same hierarchy that does map to a payment HCC — capturing the correct specificity is the highest-leverage RAF improvement available within accurate coding.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for F79 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Avoid using this code if the cause (genetic, environmental, or other) can be identified; use more specific codes instead
- •Query the provider if additional information about severity or etiology is available to allow for more precise coding
Clinical Significance
Unspecified intellectual disability is used when the provider documents intellectual disability without specifying the severity level (mild, moderate, severe, or profound). While acceptable in certain clinical contexts, this code provides less information for care planning. Intellectual disability requires lifelong support and is associated with increased comorbid medical and psychiatric conditions.
Documentation Requirements
- ✓Provider documentation of intellectual disability diagnosis
- ✓Evidence of deficits in both intellectual and adaptive functioning with onset during the developmental period
- ✓Query opportunity — always attempt to obtain severity specification from the provider
- ✓Documentation of current functional status and support needs
- ✓Assessment of comorbid conditions
Commonly Confused Codes
- •F70-F73 — Specified severity intellectual disabilities; always prefer the severity-specific code when documentation supports it
- •R41.83 — Borderline intellectual functioning; IQ 71-84, does not meet criteria for intellectual disability
- •F88 — Other disorders of psychological development; developmental delays may not meet criteria for intellectual disability
- •F81.x — Specific developmental disorders of scholastic skills; learning disabilities are not intellectual disability