Vascular dementia is the correct answer. CMS MS-DRG logic places qualifying vascular dementia diagnoses from category F01.- within MS-DRG 884, Organic Disturbances and Intellectual Disability. The FY 2026 CMS MS-DRG Definitions Manual specifically lists vascular dementia codes among the principal diagnoses assigned to MS-DRG 884.
MS-DRG assignment depends on the principal diagnosis code, major diagnostic category, procedures when applicable, and other grouper logic. Therefore, clinically related forms of dementia do not necessarily group to the same MS-DRG. Alzheimer's disease is classified primarily as a neurologic degenerative disorder and requires appropriate dementia manifestations where applicable. Alcohol-induced dementia is classified within substance-related mental and behavioral disorders, while Wernicke encephalopathy is associated with thiamine deficiency and follows different classification logic.
For CCDS practice, this question illustrates why documentation of dementia etiology and type matters. Simply documenting “dementia” can produce a less specific code and may affect MS-DRG assignment, risk adjustment, severity representation, and quality data.
The CDI specialist should seek clarification only when the clinical record supports a more specific dementia type.
CCDS Reference Topics: MS-DRG assignment; mental disorders; dementia specificity; IPPS reimbursement.
=========
