F79.9 ICD-10-CA code: Unspecified mental retardation without mention of impairment of behaviour
F79.9 is the ICD-10-CA code for “Unspecified mental retardation without mention of impairment of behaviour” in CIHI’s FY 2026–2027 release, in effect from Apr 1, 2026.
Official description
F79.9Unspecified mental retardation without mention of impairment of behaviour
Short description: Unspec mental retard wo impairment beh
ICD-10-CA · Canada · Also written F799
Notes for F79.9
As CIHI prints them, with any note F79.9 takes from the headings above it.
Includes
- Mental:• deficiency NOS• subnormality NOSFrom F79 Unspecified mental retardation
- Disorders of psychological developmentFrom Chapter 5: Mental and behavioural disorders (F00-F99)
Use additional code
Add a code for this detail when the note documents it.
- Use additional code, to identify associated conditions such as autism, other developmental disorders, epilepsy, conduct disorders, or severe physical handicap.From F70-F79 Mental retardation
Excludes
Conditions classified elsewhere.
- Symptoms, signs and abnormal clinical laboratory findings, not elsewhere classified (R00-R99)From Chapter 5: Mental and behavioural disorders (F00-F99)
Note
- A condition of arrested or incomplete development of the mind, which is especially characterized by impairment of skills manifested during the developmental period, skills which contribute to the overall level of intelligence, i.e. cognitive, language, motor, and social abilities. Retardation can occur with or without any other mental or physical condition.Degrees of mental retardation are conventionally estimated by standardized intelligence tests. These can be supplemented by scales assessing social adaptation in a given environment. These measures provide an approximate indication of the degree of mental retardation. The diagnosis will also depend on the overall assessment of intellectual functioning by a skilled diagnostician.Intellectual abilities and social adaptation may change over time, and, however poor, may improve as a result of training and rehabilitation. Diagnosis should be based on the current levels of functioning.From F70-F79 Mental retardation
Where F79.9 sits
- 1ChapterChapter 5: Mental and behavioural disorders (F00-F99)
- 2Block F70-F79Mental retardation
- 3Category F79Unspecified mental retardation
- 4Valid code F79.9Unspecified mental retardation without mention of impairment of behaviour
Source and release
- Data release
- ICD-10-CA · FY 2026–2027
- Effective date
- Apr 1, 2026
- Publisher
- CIHI
This page is built from the ICD-10-CA catalog that Vero Codes reads when it suggests codes: Canadian Institute for Health Information’s FY 2026–2027 release, imported from the publisher’s file and checked against it. The description, notes and structured data come from the same record.
Frequently asked questions
What does ICD-10-CA code F79.9 mean?
F79.9 is the ICD-10-CA code for “Unspecified mental retardation without mention of impairment of behaviour” in CIHI’s ICD-10-CA FY 2026–2027 release.
Where is F79.9 in ICD-10-CA?
F79.9 sits under F79 Unspecified mental retardation, within F70-F79 Mental retardation, within Chapter 5: Mental and behavioural disorders (F00-F99).
What coding notes apply to F79.9?
ICD-10-CA lists Includes, Note, Use additional code, Excludes notes for F79.9, including those from the headings it sits under. They are listed on this page with where each one comes from.
Which ICD-10-CA release does this page use?
It uses CIHI’s FY 2026–2027 release, in effect from Apr 1, 2026 to Mar 31, 2027. It is a reference: confirm the code against the current list and the payer’s rules before you submit it.