ICD-10 Code R41.82 Altered Mental Status, Unspecified
- ICD-10 Code R41.82 = Altered Mental Status, Unspecified.
- Used when confusion or disorientation is present but the underlying cause is unclear.
- Ensure detailed clinical documentation for proper reimbursement.
- Commonly used in emergency departments, neurology, and hospitalist billing.
- Use supporting CPT codes for diagnostic evaluations (CT, labs, E/M).
What is ICD-10 Code R41.82?
The ICD-10 code R41.82 represents Altered Mental Status, Unspecified. It is used when a patient shows changes in awareness, behavior, or cognitive function, but the exact cause (such as metabolic, infectious, or neurological) has not yet been determined.
This diagnosis code helps clinicians and medical billers document a temporary or persistent confusion, disorientation, or change in consciousness that does not meet criteria for a more specific diagnosis like dementia or delirium.
R41.82 Diagnosis Code Description (2025 Update)
- Code: R41.82
- Billable: Yes
- Description: Altered Mental Status, Unspecified
- Category: Symptoms and signs involving cognitive functions and awareness
- ICD-10-CM 2025 Effective Date: October 1, 2024
When to Use R41.82 in Medical Billing
Use R41.82 when the patient presents with confusion or cognitive changes but a definitive diagnosis (like stroke, dementia, or infection) is not yet established.
Common clinical scenarios include:
- Sudden confusion or disorientation
- Altered awareness due to medication side effects
- Post-operative confusion
- Metabolic or toxic encephalopathy (initial presentation before confirmation)
- Transient mental status changes in elderly or hospitalized patients
Related ICD-10 Codes
Condition | ICD-10 Code |
Confusion, unspecified | R41.0 |
Disorientation, unspecified | R41.3 |
Memory loss, unspecified | R41.3 |
Delirium, unspecified | R41.0 |
Altered mental status, unspecified | R41.82 |
Encephalopathy, unspecified | G93.40 |
Billing and Coding Tips for R41.82
- Always document the patient’s symptoms, onset, and suspected cause.
- Do not code R41.82 if a more specific neurological or psychiatric condition is confirmed.
- Pair with procedure codes (CPT) such as:
- 99283–99285: Emergency department visits for AMS evaluation
- 70450: CT head without contrast (if performed to assess AMS)
Medicare and commercial payers typically accept R41.82 as a medically necessary diagnosis for diagnostic tests (imaging, labs, or consultations).
Common Causes of Altered Mental Status
- Hypoglycemia or electrolyte imbalance
- Stroke or transient ischemic attack (TIA)
- Infection (e.g., UTI, sepsis, pneumonia)
- Drug or alcohol intoxication
- Dementia or psychiatric disorders
- Head injury or trauma
Final Thoughts
The R41.82 diagnosis code plays a key role in documenting Altered Mental Status (AMS) when the exact cause remains unclear. Accurate coding helps providers ensure compliant billing, avoid denials, and support effective care coordination.
If your practice handles high volumes of AMS cases or complex inpatient claims, Express Medical Billing can help you with compliant coding, claims submission, and denial prevention.
Contact Express Medical Billing today to streamline your neurology and hospital billing processes with precision and expertise.
Frequently Asked Questions (FAQs)
R41.82 is used to document altered mental status (AMS) when no specific diagnosis like delirium, dementia, or encephalopathy has been confirmed.
Yes, R41.82 is a billable ICD-10-CM code used for reimbursement and documentation in 2025.
Yes, if AMS is the main reason for the encounter and no other underlying cause is yet identified.
No. Although it involves cognitive changes, R41.82 is classified as a neurological/symptom code, not a psychiatric disorder.
- 99283–99285 (ED visits)
- 70450 (CT head)
- 99232 (subsequent hospital care)
