2026 ICD-10-CM Diagnosis Code F79Unspecified intellectual disabilities

ICD-10-CM Codes›F01–F99›F70-F79›F79

ICD-10-CM F79
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

F79 is a billable ICD-10-CM diagnosis code for unspecified intellectual disabilities. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 884. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Neurodevelopmental disorders.

F79 does not risk-adjust for Medicare Advantage under the CMS-HCC V28 model. It still risk-adjusts in the RxHCC Part D (V08) category 148 for payment year 2026.

Code Identity

ICD-10-CM Code
F79
Billable Status
Yes — Valid for Submission
Code Describes
Unspecified intellectual disabilities
Short Description
Unspecified intellectual disabilities
Same as the full description in the CMS dataset.
Chapter
F70-F79
Intellectual disabilities

Code Classification

ChapterF01–F99Mental and behavioural disorders
SectionF70-F79Intellectual disabilities
CategoryF79Unspecified intellectual disabilities
This CodeF79Unspecified intellectual disabilities

Medicare Risk Adjustment (HCC)Billing

F79 does not risk-adjust for Medicare Advantage under the CMS-HCC V28 model, but it maps to payment categories in the other CMS models shown below.

CMS-HCC V28 (Medicare Advantage Payment Model)
Not mapped
no payment category in the model that pays 100% of MA risk scores
Prior Model (CMS-HCC V24)
Not mapped under V24
this diagnosis newly risk-adjusts under the V28 model
Part D (RxHCC)
RxHCC 148 — Mild or Unspecified Intellectual Disability/Developmental Disorder
also risk-adjusts in the Part D prescription drug model (V08)

Source: CMS Payment Year 2026 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • 11p partial monosomy syndrome
  • ADNP-related multiple congenital anomalies, intellectual disability, autism spectrum disorder
  • Arachnodactyly
  • Arachnodactyly and intellectual disability with facial dysmorphism syndrome
  • Arachnodactyly with abnormal ossification and intellectual disability syndrome
  • Athetoid cerebral palsy
  • Below average intellect
  • Blepharophimosis, intellectual disability syndrome
  • Blood magnesium below reference range
  • Blood magnesium outside reference range
  • Brachycephaly
  • Brachydactyly, mesomelia, intellectual disability, heart defect syndrome
  • Brain malformations, musculoskeletal abnormalities, facial dysmorphism, intellectual disability syndrome
  • Combined malformation of central nervous system and skeletal muscle
  • Congenital dysplasia of radius
  • Congenital hepatic fibrosis
  • Congenital nuclear ophthalmoplegia
  • Congenital plicated tongue
  • Cryptorchidism, arachnodactyly, intellectual disability syndrome
  • Deletion of part of chromosome 11
  • Deletion of part of chromosome 21
  • Disorder of sex development with intellectual disability syndrome
  • DYRK1A-related intellectual disability syndrome
  • DYRK1A-related intellectual disability syndrome due to 21q22.13q22.2 microdeletion
  • Dyskinetic cerebral palsy
  • Genetic syndromic childhood obesity
  • Hepatic fibrosis, renal cyst, intellectual disability syndrome
  • Hypertelorism
  • Hypogonadism with mitral valve prolapse and intellectual disability syndrome
  • Intellectual disability
  • Intellectual disability due to nutritional deficiency
  • Intellectual disability Wolff type
  • Intellectual disability, brachydactyly, Pierre Robin syndrome
  • Intellectual disability, congenital heart disease, blepharophimosis, blepharoptosis and hypoplastic teeth
  • Intellectual disability, craniofacial dysmorphism, hypogonadism, diabetes mellitus syndrome
  • Intellectual disability, feeding difficulties, developmental delay, microcephaly syndrome
  • Intellectual disability, polydactyly, uncombable hair syndrome
  • Intellectual disability, seizures, macrocephaly, obesity syndrome
  • Intellectual disability, severe speech delay, mild dysmorphism syndrome
  • Intellectual disability, short stature, hypertelorism syndrome
  • Intellectual functioning disability
  • Kagami Ogata syndrome
  • Low intelligence
  • Mesomelic dysplasia of upper limb
  • Microcephaly, seizure, intellectual disability, heart disease syndrome
  • Micromelia
  • Non-spastic cerebral palsy
  • Ophthalmoplegia, intellectual disability, lingua scrotalis syndrome
  • Osteogenesis imperfecta, retinopathy, seizures, intellectual disability syndrome
  • Paralysis of tongue
  • Pervasive developmental disorder with disorder of intellectual development with loss of previously acquired skills
  • Pervasive developmental disorder with disorder of intellectual development without loss of previously acquired skills
  • Plicated tongue
  • Polyneuropathy, intellectual disability, acromicria, premature menopause syndrome
  • Premature ovarian failure
  • Primary hypomagnesemia, generalized seizures, intellectual disability, obesity syndrome
  • Robin sequence
  • Severe microbrachycephaly, intellectual disability, athetoid cerebral palsy syndrome
  • WAGR syndrome
  • White matter hypoplasia, corpus callosum agenesis, intellectual disability syndrome
  • White Sutton syndrome

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Mental deficiency NOS
  • Mental subnormality NOS

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR MBD014
Neurodevelopmental disorders
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Intellectual Disability

    subnormal intellectual functioning which originates during the developmental period. this has multiple potential etiologies, including genetic defects and perinatal insults. intelligence quotient (iq) scores are commonly used to determine whether an individual has an intellectual disability. iq scores between 70 and 79 are in the borderline range. scores below 67 are in the disabled range. (from joynt, clinical neurology, 1992, ch55, p28)

  • X-Linked Intellectual Disability

    a class of genetic disorders resulting in intellectual disability that is associated either with mutations of genes located on the x chromosome or aberrations in the structure of the x chromosome (sex chromosome aberrations).

  • Hypertelorism

    abnormal increase in the interorbital distance due to overdevelopment of the lesser wings of the sphenoid.

  • Arachnodactyly

    an abnormal bone development that is characterized by extra long and slender hands and fingers, such that the clenched thumb extends beyond the ulnar side of the hand. arachnodactyly can include feet and toes. arachnodactyly has been associated with several gene mutations and syndromes.

  • WAGR Syndrome

    a contiguous gene syndrome associated with hemizygous deletions of chromosome region 11p13. the condition is marked by the combination of wilms tumor; aniridia; genitourinary abnormalities; and intellectual disability.

  • Congenital Hepatic Fibrosis

    a congenital disorder usually inherited in an autosomal recessive pattern. it affects the hepatobiliary system and the kidneys. it is characterized by liver fibrosis, portal hypertension, and renal cysts.

Patient EducationClinical

Developmental Disabilities

Developmental disabilities are conditions that are usually present at birth. They can affect a child's growth and development. These conditions can cause physical, learning, language, or behavior issues. They can include:

The full article covers:

  • What are developmental disabilities?
  • What causes developmental disabilities?
  • How are developmental disabilities diagnosed?
  • What are the treatments for developmental disabilities?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert F79 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
319 Intellect disability NOS
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About F79Overview

What is the ICD-10 code for unspecified intellectual disabilities?

The ICD-10-CM code for unspecified intellectual disabilities is F79. It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

Is F79 (Unspecified intellectual disabilities) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report unspecified intellectual disabilities on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does F79 group to?

When unspecified intellectual disabilities is the principal diagnosis on an inpatient stay, it groups to MS-DRG 884 (organic Disturbances and Intellectual Disability), which carries a relative weight of 1.6089. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of F79?

Under the General Equivalence Mappings, unspecified intellectual disabilities converts to ICD-9-CM 319 (intellect disability NOS). The mapping is approximate, so confirm the match fits the documentation.

Does F79 risk-adjust for Medicare Advantage payment?

Not for Medicare Advantage: F79 maps to no category in the CMS-HCC V28 model. It still risk-adjusts in the RxHCC Part D (V08) category 148 (Mild or Unspecified Intellectual Disability/Developmental Disorder).