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v1.0.0
ICD-10 Guide
DiagnosesAltered Mental Status

Altered Mental Status

ICD-10 Coding for Altered Mental Status(R41.82, F05)

PRIMARY SPECIALTYEmergency Medicine
COMPLEXITYHigh
LAST UPDATED09/15/2025
Sam Tuffun, PT, DPT
Physical Therapist | Medical Coding & Billing Contributor

Diagnosis Overview

What is Altered Mental Status?
Essential facts and insights about Altered Mental Status

Key Clinical Considerations:

  • Altered mental status may present with confusion, disorientation, agitation, lethargy, or decreased responsiveness.
  • Laboratory findings may include abnormal electrolyte levels, glucose levels, or toxicology screens indicating substance use.
  • Physical examination may reveal changes in vital signs, neurological deficits, or signs of infection.
  • Imaging studies such as CT or MRI may show structural abnormalities, hemorrhages, or signs of stroke.
  • Severity can be assessed using scales such as the Glasgow Coma Scale (GCS) to determine the level of consciousness.

Clinical Information

Clinical Criteria & Documentation Requirements

  • Document the patient's mental status changes, including onset, duration, and associated symptoms.
  • Use specific terminology such as 'confusion', 'delirium', or 'dementia' as appropriate.
  • Examples include: 'Patient presents with acute confusion and disorientation to time and place.'
  • Document medical necessity by linking altered mental status to underlying conditions or acute events.
  • Quality measures may require documentation of cognitive assessments and interventions.

Coding Guidelines

Usage Guidelines & Examples

  • Use R41.82 for altered mental status due to acute conditions; use F05 for delirium due to underlying medical conditions.
  • Do not use R41.82 for chronic cognitive disorders like dementia; use appropriate codes for those conditions.
  • R41.82 is distinct from codes for specific psychiatric disorders (e.g., F01-F99) that have different treatment implications.
  • Common errors include misclassifying acute confusion as chronic cognitive impairment; ensure accurate history is documented.
  • In complex cases, consider the underlying cause of altered mental status to select the most appropriate code.

Code Exclusions

Important Exclusions

  • Excludes conditions like dementia (F00-F03) and specific psychiatric disorders (F04-F99).
  • Alternative codes for excluded conditions include F01 for vascular dementia and F03 for unspecified dementia.
  • Conditions are excluded due to the chronic nature of dementia versus acute altered mental status.
  • Common mistakes include using altered mental status codes for chronic conditions without proper documentation.
  • Related but distinct conditions include transient ischemic attacks (TIA) and acute confusional states.

Related ICD-10 Codes

Primary Codes
R41.82
Altered mental status
F05
Delirium due to underlying medical condition
Ancillary Codes
Z00.6
N39.0
Differential Codes
F05
F05
when AMS is due to a known medical condition, confirmed by clinical findings.
F03.90
F03.90
for chronic cognitive decline without acute changes.
R41.82
R41.82
when no specific cause is identified.

Related CPT Codes

CPT codes will be available in a future update.

Specialty Focus

Primary Specialty

Emergency Medicine

Specialty Applications

  • Applies to conditions such as infections, metabolic imbalances, and substance intoxication.
  • Patient populations include all ages, with increased risk in elderly and those with comorbidities.
  • Clinical settings include emergency departments, inpatient units, and outpatient follow-ups.
  • Specialty-specific applications may involve neurology, psychiatry, and geriatrics.
  • Used in treatment contexts such as acute care, rehabilitation, and palliative care.

Coding Complexity

High Complexity

This diagnosis requires careful attention to:

  • Comprehensive clinical documentation
  • Accurate code selection based on clinical criteria
  • Proper exclusion considerations
  • Specialty-specific coding guidelines

Documentation

Documentation Templates

Template 1

Template: 'Patient diagnosed with altered mental status based on clinical findings of confusion and disorientation.'

Template 2

Template: 'Clinical presentation consistent with altered mental status including agitation and lethargy.'

Template 3

Template: 'Diagnostic criteria for altered mental status met as evidenced by abnormal lab results and physical examination.'

Template 4

Template: 'Treatment plan initiated for altered mental status with interventions including hydration and monitoring.'

Template 5

Template: 'Follow-up care for altered mental status including monitoring cognitive function and vital signs.'

Billing Information

Billing Considerations

  • Ensure proper documentation for billing
  • Verify code specificity requirements
  • Check for any additional codes needed
  • Review payer-specific guidelines

Common Issues

  • Insufficient clinical documentation
  • Incorrect code selection
  • Missing supporting diagnoses
  • Timing and frequency documentation

Frequently Asked Questions

What documentation is required for this diagnosis?

Document the patient's mental status changes, including onset, duration, and associated symptoms.

How does this differ from similar diagnoses?

Altered mental status is acute and often reversible, while dementia is chronic and progressive.

What are common billing considerations?

Ensure medical necessity is documented, linking altered mental status to acute conditions for reimbursement.

What procedures are typically associated?

Related CPT codes may include neuroimaging, laboratory tests, and cognitive assessments.

Are there any quality reporting implications?

Quality measures may require documentation of cognitive assessments and interventions for altered mental status.