F79 ICD-10-CM Code: Unspecified intellectual disabilities
F79 is not a CMS-HCC payment code. MEAT criteria · RAF Calculator · HCC Buddy coding tools
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FY 2026 Apr update / Mental, Behavioral and Neurodevelopmental disorders (F01-F99) / Intellectual Disabilities (F70-F79)
F79
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceUnspecified 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.
Buddy Insight
Unspecified intellectual disability is used when the provider documents intellectual disability without specifying the severity level (mild, moderate, severe, or profound).
CMS-HCC V28
N/A—
Not mapped
CMS-HCC V24
HistoricalHistorical
Not used for CY2026 payment
ACA/HHS
N/A—
Not mapped
ESRD/PACE
N/A—
Not mapped
RXHCC
MappedHCC 148
Code-level coefficient reference
Code Book Path
Inclusion Terms
Official- Mental deficiency NOS
- Mental subnormality NOS
Excludes 2
Official- symptoms, signs and abnormal clinical laboratory findings, not elsewhere classified (R00-R99)Inherited from F01-F99
Related Codes
No related codes are included in this display for F79. Check the Code Book for the complete code path.
Includes
Official- disorders of psychological developmentInherited from F01-F99
Excludes 1
Official- borderline intellectual functioning, IQ above 70 to 84 (R41.83)Inherited from F70-F79
Code First
Official- any associated physical or developmental disordersInherited from F70-F79
Use Additional
OfficialNo Use Additional Code instructions are included in this display for F79. Check the code and parent instructions in the Code Book.
Code Also
OfficialNo Code Also instructions are included in this display for F79. Check the code and parent instructions in the Code Book.
Buddy Documentation Tip
MEAT Support
Audit Caution
Common Mistakes
Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →
Is F79 an HCC code?
F79 has no mapping under the current CMS-HCC V28 community payment model. F79 has a separate mapping under the Part D RxHCC model (HCC 148 (Mild or Unspecified Intellectual Disability/Developmental Disorder)); the applicable result needs member context.
- Code
- F79
- Description
- Unspecified intellectual disabilities
- HCC (V28)
- No CMS-HCC V28 mapping
- RAF reference coefficient
- —
- Billable
- Yes
- Payment year
- 2026
HCC Category Mapping
These are source-labeled model coefficients, not member totals. A category may still be removed by hierarchy or model cleanup rules. Weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. Actual per-patient RAF contribution depends on member context, hierarchy and cleanup rules, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains available for historical review.
Work F79 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →
MEAT review for F79
For F79, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule.
- 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
Coder workflow notes
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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 has no mapping under the current CMS-HCC V28 community payment model. F79 has a separate mapping under the Part D RxHCC model (HCC 148 (Mild or Unspecified Intellectual Disability/Developmental Disorder)); the applicable result needs member context. Do not assign V28 risk adjustment value from this page; verify the applicable model and payment year before using this code for risk adjustment.
Avoid using this code if the cause (genetic, environmental, or other) can be identified; use more specific codes instead.
HCC Buddy maintains structured V28 and V24 mapping, source-labeled coefficient references, 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