F79 — Unspecified intellectual disabilities
Is F79 billable?
Yes, but F79 is an unspecified code. F79 is a valid, billable ICD-10-CM code for encounters from October 1, 2026 through September 30, 2027. However, F79 is an unspecified or catch-all code. Payers apply additional scrutiny to unspecified codes and many deny them when the medical record supports a more specific option, so check the documentation before selecting F79.
F79 at a glance
| Code | F79 |
|---|---|
| Description | Unspecified intellectual disabilities |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
Which MS-DRGs does F79 group to?
F79 sits in MDC 19 and helps define the logic of 1 MS-DRG (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.
- 884Organic Disturbances and Intellectual Disabilitymedical
How is F79 listed in the Alphabetic Index?
These are the routes through the Alphabetic Index that lead to F79. They show the wording a clinician may have documented, which often differs from the Tabular description.
- Development › tardy, mental
- Disability, disabilities › intellectual
Inclusion terms
Alternative wording in documentation that is classified to F79.
- Mental deficiency NOS
- Mental subnormality NOS
Excludes1 — never code together — inherited from F70-F79
The conditions below can never be reported together with F79 on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.
- borderline intellectual functioning, IQ above 70 to 84 (R41.83)
Code first — inherited from F70-F79
The underlying condition below must be sequenced before F79. F79 describes a manifestation and cannot be the principal or first-listed diagnosis.
- any associated physical or developmental disorders
Excludes2 — not included here — inherited from Chapter 5
The conditions below are not part of F79, but a patient may have both at the same time. When documentation supports it, F79 and the excluded code may both be reported.
- symptoms, signs and abnormal clinical laboratory findings, not elsewhere classified (R00-R99)
How long has F79 existed?
F79 has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.