ICD-10-CM 2027
ICD-10 code for Altered mental status
Confirmed by the official ICD-10-CM index entry “alteration (of), altered › mental status”. Page updated September 29, 2026.
About coding Altered mental status
The ICD-10-CM code for Altered mental status is R41.82 (Altered mental status, unspecified).
It is also searched as AMS.
Within R41.8, choose R41.82 (Altered mental status, unspecified) only when documentation doesn't support a more specific option: age-related cognitive decline (R41.81), borderline intellectual functioning (R41.83), other specified cognitive deficit (R41.84), Anosognosia (R41.85) and other symptoms and signs involving cognitive functions and awareness (R41.89).
Don't report R41.82 together with the conditions in its Excludes1 note: altered level of consciousness (R40.-), altered mental status due to known condition - code to condition and delirium NOS (R41.0).
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
Don't confuse with (Excludes1 for R41.82)
Common questions about Altered mental status ICD-10 codes
What is the ICD-10 code for Altered mental status?
- R41.82 — Altered mental status, unspecified.
Is R41.82 billable?
- Yes. R41.82 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can R41.82 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict R41.82 as a principal diagnosis.
Is R41.82 a CC or MCC?
- No. R41.82 is neither a CC nor an MCC under MS-DRG v44.0.