heimer’s disease genetic mutation from either genetic testing or family history, and all
three of the following are present:
1. Clear evidence of decline in memory and learning.
2. Steadily progressive, gradual decline in cognition, without extended plateaus.
3. No evidence of mixed etiology (i.e., absence of other neurodegenerative or cere-
brovascular disease, or another neurologica l or systemic disease or condition likely
contributing to cognitive decline).
D. The disturbance is not better explained by cerebrovascular disease, another neurode-
generative disease, the effects of a substance, or another mental, neurological, or sys-
temic disorder.
Coding note: For probable major neurocognitive disorder due to Alzheimer’s disease,
with behavioral disturbance, code first 331.0 (G30.9)  Alzheimer’s disease, followed by
294.11 (F02.81)  major neurocognitive disorder due to Alzheimer’s disease. For probable
neurocognitive disorder due to Alzheimer’s disease, without behavioral disturbance, code
first 331.0 (G30.9)  Alzheimer’s disease, followed by 294.10 (F02.80)  major neurocognitive
disorder due to Alzheimer’s disease, without behavioral disturbance.
For possible major neurocognitive disor der due to Alzheimer’s disease, code 331.9
(G31.9)  possible major neurocognitive disorder due to Alzheimer’s disease. ( Note:  Do not
use the additional code for Alzheimer’s disease. Behavioral disturbance cannot be coded
but should still be indicated in writing.)