G31.84 - Mild cognitive impairment of uncertain or unknown etiology

Version 2023
Replaced Code
Billable Code
Revised Code
Convert to ICD-9
ICD-10:G31.84
Short Description:Mild cognitive impairment of uncertain or unknown etiology
Long Description:Mild cognitive impairment of uncertain or unknown etiology
Status: Valid for Submission
Version:ICD-10-CM 2023
Code Classification:
  • Diseases of the nervous system (G00–G99)
    • Other degenerative diseases of the nervous system (G30-G32)
      • Oth degenerative diseases of nervous system, NEC (G31)

G31.84 is a billable ICD-10 code used to specify a medical diagnosis of mild cognitive impairment of uncertain or unknown etiology. The code is valid during the fiscal year 2023 from October 01, 2022 through September 30, 2023 for the submission of HIPAA-covered transactions.

Approximate Synonyms

The following clinical terms are approximate synonyms or lay terms that might be used to identify the correct diagnosis code:

Revised 2023 ICD-10 Code

G31.84 was revised for the FY 2023, effective October 1, 2022.

Replaced Code

This code was replaced in the 2023 ICD-10 code set with the code(s) listed below. The National Center for Health Statistics (NCHS) has published an update to the ICD-10-CM diagnosis codes which became effective October 1, 2022. This code was replaced for the FY 2023 (October 1, 2022 - September 30, 2023).


  • F06.70 - Mild neurocog disord d/t known physiol cond w/o beh distrb
  • F06.71 - Mild neurocog disord d/t known physiol cond with beh distrb

Tabular List of Diseases and Injuries

The Tabular List of Diseases and Injuries is a list of ICD-10 codes, organized "head to toe" into chapters and sections with coding notes and guidance for inclusions, exclusions, descriptions and more. The following references are applicable to this diagnosis code:


Inclusion Terms

Inclusion Terms
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.

Use Additional Code

Use Additional Code
The “use additional code” indicates that a secondary code could be used to further specify the patient’s condition. This note is not mandatory and is only used if enough information is available to assign an additional code.

Type 1 Excludes

Type 1 Excludes
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 Injuries References

The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10 code(s). The following references for this diagnosis code are found in the injuries and diseases index:

Convert to ICD-9 Code

Source ICD-10 CodeTarget ICD-9 Code
G31.84331.83 - Mild cognitive impairemt

Patient Education


Mild Cognitive Impairment

Some forgetfulness can be a normal part of aging. However, some people have more memory problems than other people their age. This condition is called mild cognitive impairment, or MCI. People with MCI can take care of themselves and do their normal activities.

MCI memory problems may include:

Memory problems can also have other causes, including certain medicines and diseases that affect the blood vessels that supply the brain. Some of the problems brought on by these conditions can be managed or reversed.

Your health care provider can do thinking, memory, and language tests to see if you have MCI. You may also need to see a specialist for more tests. Because MCI may be an early sign of Alzheimer's disease, it's really important to see your health care provider every 6 to 12 months.

At this time, there is no proven drug treatment for MCI. Your health care provider can check to see if you have any changes in your memory or thinking skills over time.

NIH: National Institute on Aging


[Learn More in MedlinePlus]

What is Mild Cognitive Impairment?

Some people with memory problems have a condition called mild cognitive impairment, or MCI. MCI has several types.
[Learn More in MedlinePlus]

Code History

Previous Code: G31.83

Parent Code: G31.8

Next Code: G31.85