F79 — Unspecified intellectual disabilities
F79 is a billable, specific ICD-10-CM code for unspecified intellectual disabilities. It is valid for submission on a claim.
Inclusion terms
Alternative wordings a physician may use in the chart for this same code.
- Mental deficiency NOS
- Mental subnormality NOS
Other codes that can never be billed with F79
These codes carry an Excludes1 note pointing at F79. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading F79 alone.
- R41.83Borderline intellectual functioning
Risk adjustment
F79 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.
Medicare coverage
F79 is named in 5 Medicare coverage policies — 3 listing it as supporting medical necessity, and 2 listing it as NOT covered. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.
- A52434Health and Behavior Assessment/Intervention – Medical Policy Articlenot covered
- A56937Billing and Coding: Psychiatry and Psychology Servicesnot covered
- A57361Billing and Coding: Monitored Anesthesia Care
- A57434Billing and Coding: Vestibular and Audiologic Function Studies
How F79 is indexed
Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to F79.
- Development›tardy, mental
- Disability, disabilities›intellectual
Questions about F79
- Is F79 a billable ICD-10-CM code?
- Yes. F79 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
- Where does F79 sit in the tabular list?
- Mental, Behavioral and Neurodevelopmental disorders (F01-F99), in the block Intellectual Disabilities (F70-F79).