The Summer Foundation has made the request as disability-supported homes sit vacant across Australia, including in Canberra, while hospital-bound participants are unable to move into them amid delays processing paperwork and approving funding.

The organisation believes fixing the problem would help prevent participants being forced into aged care homes, while also sparking major private sector spending on the construction of new social housing.

It could also save taxpayers more than $400 million a year, according to the foundation, which says the cost of a hospital stay is twice as expensive as supporting a participant to live in the community.

The Canberra Times last month reported NDIS participants were spending months stuck in local hospitals despite being medically cleared to leave, with bureaucratic delays in processing paperwork blamed for holding up their release into the community.

As of last October more than 1000 participants nationwide were in public hospitals unable to be discharged, occupying beds for months at a time at a cost to the taxpayer of some $531 million.

In a submission to the government ahead of the March 29 budget, the Summer Foundation is calling for a $54 million package of measures to speed up hospital discharge rates and help the government meet its targets for avoiding admissions of young people into aged care.

The foundation's pitch includes $37.5 million over three years to help hospital staff identify suitable housing options for patients.

The submission argues that supply of supported accommodation is not the main barrier to a participant's release from hospital, pointing to figures which show 3000 properties are sitting vacant across the country - including at least 10 in Canberra.

Rather, it is blaming the National Disability Insurance Agency's delays in allocating funding to participants for suitable housing.

It wants the agency to make housing funding decisions for hospital-bound participants within three days, compared to the more than 60 it says it currently takes.

The Summer Foundation's head of government relations and policy, Amelia Condi, said participants were entering aged care homes rather than transitioning into suitable accommodation because of the delays.

"And we know that once someone enters aged care, it is much more difficult to get them out - if they ever get out," she said.

The Morrison government has a target of having no person under 65 entering aged care by this year, and no one under that aged threshold living in a nursing home by 2025 - unless under exceptional circumstances.

The latest report on progress against the targets showed more than 700 people under 65 entered nursing homes in the 12 months to June 2021, a 43 per cent reduction on the number from the previous financial year.

About 3900 people aged under 65 were living in aged care homes as of June 2021, down 20 per cent from the previous year.

In statements to The Canberra Times, neither the agency, Department of Social Services or NDIS Minister Linda Reynolds commented on whether the upcoming budget would include extra funding to speed up hospital discharge rates.

A department spokesperson said the agency had implemented a number of measures to tackle the problem, but conceded there was work to be done.

"it is critical that the NDIA and state and territory health systems continue to collaborate on ensuring that NDIS participants do not stay in hospital any longer than is necessary," the spokesperson said.

ACT government and Commonwealth representatives have met three times in recent weeks as part of a renewed effort to fix the problem in the nation's capital.

An agency spokesperson said decisions about funding supported accommodation - which was for people with "extreme functional limitations" or very high support needs who met specific criteria - were being made in line with the legislation.

Almost 17000 participants had housing funding in their plan as of the end of 2021, with the agency predicting that number will continue to rise.

The federal agencies said state and territory governments were responsible for social housing.