2026 ICD-10-CM Diagnosis Code R41.83Borderline intellectual functioning
R41.83 is a billable ICD-10-CM diagnosis code for borderline intellectual functioning. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). The code is not accepted as a principal diagnosis by the Medicare Code Editor. As a symptom code, it should not be used as a principal diagnosis once a related definitive diagnosis has been established. Coders also document this condition as below average intellect. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Nervous system signs and symptoms.
Code Identity
Code Classification
Code EditsBilling
Medicare Code Editor checks that affect claim validity for R41.83.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Below average intellect
- Borderline intellectual disability
- Intelligence quotient low
- Low intelligence
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Inclusion Terms
- IQ level 71 to 84
Type 1 Excludes
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
- Functioning, intellectual, borderline - R41.83
- Symptoms NEC - R68.89
- borderline intellectual functioning - R41.83
- borderline intellectual functioning - R41.83
External Cause of Injuries IndexGuidance
References for this code in the External Cause of Injuries Index.
- Functioning, intellectual, borderline
- Symptoms NEC
- involving
- awareness
- borderline intellectual functioning
- Symptoms NEC
- involving
- cognitive functions
- borderline intellectual functioning
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Patient EducationClinical
Mental Disorders
Mental disorders (or mental illnesses) are conditions that affect your thinking, feeling, mood, and behavior. They may happen over a short period of time or come and go. Some can be chronic (long-lasting). They can affect your ability to relate to others and function each day..
The full article covers:
- What are mental disorders?
- What are some types of mental disorders?
- What causes mental disorders?
- Who is at risk for mental disorders?
- How are mental disorders diagnosed?
- What are the treatments for mental disorders?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert R41.83 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About R41.83Overview
Is R41.83 a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report borderline intellectual functioning on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
Can R41.83 be a principal diagnosis?
No. The Medicare Code Editor rejects this code as a principal diagnosis because borderline intellectual functioning describes a circumstance that influences health status rather than a current illness. Report it as a secondary diagnosis.
What is the ICD-9 equivalent of R41.83?
Under the General Equivalence Mappings, borderline intellectual functioning converts to ICD-9-CM V62.89 (psychological stress NEC). The mapping is approximate, so confirm the match fits the documentation.
Footnotes
[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.
