ICD-10 Code R41.82 Altered Mental Status, Unspecified

ExpressMBS Editorial Team — Fri, 14 Mar 2025 20:09:03 +0000

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.