Is alzheimer's disease inherited?

Likely yes. If there is a strong history of alzheimer's disease in the family like grandparents, parents, uncles, aunts, brothers or sisters, then you could be at risk of developing it.
Some types yes. Alzheimer's disease with early onset at ages 40 to 60 has a large genetic component while alzheimer's with a late onset has a small genetic component.
Small percentage. There is a small percentage of Alzheimer's disease that's felt to be hereditary. Can do genetic testing to further delineate this issue.
Genetics. There are rare families with genetic risks, such as presenilin i or ii, and amyloid precursor protein mutations. Apoe epsilon 4 homozygous states can increase risk.