324 people are in Dublin
Over 1,200 people under the age of 65 are living in nursing homes.
The Disabilities Federation of Ireland says many are there because of a lack of resources for them to live in the community.
Of the 1,250 people under the age of 65 who are living in nursing homes, 706 are male and 544 are female.
There are 324 people in Dublin and 125 in Cork, while every region in Ireland also has several people under-65 in nursing homes.
The HSE says a number of them may have acquired injuries, as a result of road traffic collisions and other trauma.
It says, in some instances, people under 65 are appropriately placed in nursing homes.
The HSE says the 2022/23 National Service Plan allocated €5.5 million to enable 63 people under 65 to move from nursing homes to the community.