Carlene MacMillan, MD

The ICD 10 Code for Alterned Mental Status: R41.82

ICD 10


min read

March 28, 2024


altered mental status

billing code

Navigating the Complexities of ICD-10 Coding for Altered Mental Status

Understanding and accurately coding for altered mental status using the ICD-10 system is crucial in healthcare. This comprehensive guide will delve into the specifics of the ICD-10 code for altered mental status, offering insights into its application, challenges, and best practices for healthcare professionals.

Altered Mental Status ICD-10 Code Specifics

The ICD-10 code for altered mental status, unspecified, is designated as R41.82. It's essential for mental healthcare providers to understand this specific code, ensuring accurate billing and patient care. R41.82 is considered by payers to be a billable code for reimbursement purposes.

What Not to Include

When coding for R41.82, avoid using descriptors like altered level of consciousness (R40), or delirium NOS (R41.0). If the altered mental state is due to a known condition, code for that specific condition instead.

Possible Causes of Altered Mental Status

Altered mental status can result from a variety of causes, including adrenal or thyroid diseases, brain tumors, dehydration, drug or alcohol withdrawal, and more. Recognizing these causes is vital for accurate diagnosis and coding.

Importance of Detailed Documentation

Accurate coding requires detailed documentation of symptoms and potential causes. For example, if the altered mental state is due to medication side effects or a recent head injury, this information should be clearly documented.

Using the Correct Code

In cases where no specific cause for the altered mental state is identified, the code "R41.9 – Other symptoms and signs involving cognitive functions and awareness, unspecified" may be used. This code is only applicable when no further information is available.

Differential Diagnosis in Altered Mental States

Understanding the differential diagnosis is crucial for determining the underlying cause. Conditions like delirium, dementia, encephalopathy, psychiatric conditions, and substance intoxication or withdrawal can all lead to altered mental states. Each condition may require different ICD-10 codes based on the clinical assessment.

Altered Mental Status without a Specific Diagnosis

In cases with no definitive diagnosis, the code "R41.9" could be used. However, it's important to strive for specificity and update the diagnosis as more information becomes available.

Clinical Example: Unspecified Altered Mental Status

Consider a case where a patient presents with confusion and disorientation, but no clear etiology is identified. Initially, "R41.9" may be used, but further evaluation is necessary for a more precise diagnosis.

Conclusion: Accurate Coding for Optimal Care

Accurate ICD-10 coding for altered mental status is not just a billing requirement; it's a critical component of patient care. By understanding the specific codes, adhering to guidelines, and ensuring thorough documentation, healthcare professionals can enhance the accuracy of their diagnoses, leading to better patient outcomes.


If you, or someone you know, is in crisis or needs immediate assistance, please call 911 immediately. To talk to someone now, please call the National Suicide Prevention Lifeline at 1-800-273-8255.

Osmind Inc. © 2024 All Rights Reserved.