How many older Americans have Alzheimer’s, how sharply does the chance rise with age, and what does the APOE e4 gene, the genetic risk the original version of this page asked about, actually tell a person? The newest answers come from the Alzheimer’s Association’s 2026 Alzheimer’s Disease Facts and Figures, its annual statistical report on the United States.
About 1 in 9 Americans age 65 and older
An estimated 7.4 million Americans age 65 and older are living with clinical Alzheimer’s dementia in 2026. That is about 1 in 9 people (11%) in that age group, according to the 2026 estimate. The figure covers Americans 65 and older only, not people of all ages.
Age is the biggest factor
The share of people living with Alzheimer’s dementia climbs steeply with age.
| Age group | Share with Alzheimer’s dementia, 2026 estimate |
|---|---|
| 65 to 74 | 5.2% |
| 75 to 84 | 13.8% |
| 85 and older | 35.8% |
The share at 85 and older is about 7 times the share at 65 to 74 (our arithmetic). Of the 7.4 million people living with Alzheimer’s dementia, 74% are 75 or older.
Who is living with it
Almost two thirds of Americans with Alzheimer’s are women: of the 7.4 million people age 65 and older, an estimated 4.5 million are women and 2.9 million are men in 2026.
People younger than 65 can also develop clinical Alzheimer’s dementia. Although prevalence studies of younger onset dementia in the US are limited, researchers believe about 110 of every 100,000 people age 30 to 64, or about 200,000 Americans in total, have younger onset dementia.
The APOE e4 gene
Of the many genetic variants known to raise risk, the e4 form of the APOE gene has the strongest effect on late onset Alzheimer’s dementia. Inheriting one copy raises risk, and two copies raise it further, but having e4 does not guarantee that a person will develop the disease.
Based on a study in Europe and a study in the United States, among people aged 65 to 69, the risk of developing dementia by their early to mid 80s was 5% to 7% for those with no copies of e4, 15% to 16% for those with one copy and 31% to 40% for those with two. Those are study ranges for one age group, not odds for everyone.
Genetic testing
The original page asked whether people would want to learn their genetic risk. The 2026 report says routine APOE e4 testing is not recommended at this time. Health care professionals do request the test for people considering the treatments lecanemab and donanemab, because people with e4 face a higher risk of side effects from those drugs.
Among Americans diagnosed with Alzheimer’s dementia, a review of 20 published articles found that 56% had one copy of e4 and 11% had two.
Looking ahead
By 2060, the number of Americans age 65 and older with clinical Alzheimer’s dementia is projected to reach 13.8 million, nearly double the 2026 estimate (our arithmetic), barring breakthroughs that prevent or cure the disease.
The short version
About 1 in 9 Americans age 65 and older, an estimated 7.4 million people, live with Alzheimer’s dementia in 2026. The share rises from 5.2% at ages 65 to 74 to 35.8% at 85 and older.
Last checked: 2026-10-22, against the Alzheimer’s Association 2026 Alzheimer’s Disease Facts and Figures. This article was machine-checked against the sources above and has not been expert-reviewed. Spotted an error or a newer public figure? Please tell us on our contact page with the article link and we will review it.
Sources
- S1 Alzheimer’s Association. 2026 Alzheimer’s Disease Facts and Figures. Alzheimers Dement 2026;22. https://doi.org/10.1002/alz.71345 (full report PDF at https://www.alz.org/getmedia/ef8f48f9-ad36-48ea-87f9-b74034635c1e/alzheimers-facts-and-figures.pdf ; open access at https://pmc.ncbi.nlm.nih.gov/articles/PMC13098189/ ). Accessed Oct 22, 2026.
- S2 Alzheimer’s Association. Alzheimer’s Disease Facts and Figures (web summary). https://www.alz.org/alzheimers-dementia/facts-figures Accessed Oct 22, 2026.