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ICD-10 Guide
ICD-10 CodesG31.84

G31.84

Billable

Mild cognitive impairment of uncertain or unknown etiology

BILLABLE STATUSYes
IMPLEMENTATION DATEOctober 1, 2015
LAST UPDATED09/05/2025

Code Description

ICD-10 G31.84 is a billable code used to indicate a diagnosis of mild cognitive impairment of uncertain or unknown etiology.

Key Diagnostic Point:

Mild cognitive impairment (MCI) of uncertain or unknown etiology is characterized by noticeable cognitive decline that is greater than expected for an individual's age and education level, but not severe enough to interfere significantly with daily life. This condition often serves as a transitional stage between normal cognitive aging and more serious neurodegenerative diseases, such as Alzheimer's disease. Patients may exhibit memory problems, difficulty with attention, and challenges in executive function. The etiology of MCI can be multifactorial, including genetic predispositions, lifestyle factors, and comorbid medical conditions. It is crucial to differentiate MCI from other forms of dementia, as early identification can lead to interventions that may slow cognitive decline. Assessment typically involves comprehensive cognitive testing, neuroimaging, and evaluation of functional abilities. The uncertainty surrounding the etiology of MCI complicates diagnosis and treatment, making it essential for healthcare providers to conduct thorough evaluations and consider a range of potential underlying causes.

Code Complexity Analysis

Complexity Rating: Medium

Medium Complexity

Complexity Factors

  • Differentiation from other cognitive disorders
  • Assessment of etiology is often unclear
  • Requires comprehensive documentation of cognitive testing
  • Potential overlap with Alzheimer's and other dementias

Audit Risk Factors

  • Inadequate documentation of cognitive assessments
  • Failure to specify the degree of cognitive impairment
  • Lack of follow-up notes on patient progress
  • Misdiagnosis due to overlapping symptoms with other conditions

Specialty Focus

Medical Specialties

Neurology

Documentation Requirements

Detailed cognitive assessment results, neuroimaging reports, and functional status evaluations.

Common Clinical Scenarios

Patients presenting with memory complaints, difficulty in daily activities, or family concerns about cognitive decline.

Billing Considerations

Neurologists should ensure that all cognitive tests are documented and that differential diagnoses are considered.

Geriatrics

Documentation Requirements

Comprehensive geriatric assessments, including cognitive, functional, and social evaluations.

Common Clinical Scenarios

Older adults with gradual cognitive decline, family history of dementia, or comorbidities affecting cognition.

Billing Considerations

Geriatricians should focus on the impact of comorbid conditions on cognitive function and document any interventions or referrals.

Coding Guidelines

Inclusion Criteria

Use G31.84 When
  • According to ICD
  • 10 coding guidelines, G31
  • 84 should be used when there is evidence of mild cognitive impairment without a clear etiology
  • Coders must ensure that the diagnosis is supported by clinical documentation and cognitive assessment results

Exclusion Criteria

Do NOT use G31.84 When
No specific exclusions found.

Related ICD-10 Codes

Related CPT Codes

96116CPT Code

Neuropsychological testing

Clinical Scenario

Used to assess cognitive function in patients suspected of having MCI.

Documentation Requirements

Results of cognitive tests and interpretation must be documented.

Specialty Considerations

Neurologists and psychologists should ensure comprehensive reporting of test results.

ICD-10 Impact

Diagnostic & Documentation Impact

Enhanced Specificity

ICD-10 Improvements

The transition to ICD-10 has allowed for more precise coding of cognitive disorders, including MCI. This specificity aids in better tracking of patient outcomes and resource allocation for cognitive health.

ICD-9 vs ICD-10

The transition to ICD-10 has allowed for more precise coding of cognitive disorders, including MCI. This specificity aids in better tracking of patient outcomes and resource allocation for cognitive health.

Reimbursement & Billing Impact

The transition to ICD-10 has allowed for more precise coding of cognitive disorders, including MCI. This specificity aids in better tracking of patient outcomes and resource allocation for cognitive health.

Resources

Clinical References

  • •
    Alzheimer's Association
  • •
    National Institute on Aging

Coding & Billing References

  • •
    Alzheimer's Association
  • •
    National Institute on Aging

Frequently Asked Questions

What is the difference between MCI and dementia?

Mild cognitive impairment (MCI) is characterized by noticeable cognitive decline that does not significantly impair daily functioning, while dementia involves more severe cognitive impairment that interferes with daily activities and independence.

How is MCI diagnosed?

MCI is diagnosed through a combination of clinical evaluations, cognitive testing, and assessments of daily functioning. Neuroimaging may also be used to rule out other conditions.