A new survey of hundreds of federally sponsored local agencies that assist aging Americans has found increased efforts to help the elderly remain in their homes as they grow older, a policy known as aging in place.

A 2013 survey by the National Association of Area Agencies on Aging found that more than 70 percent of local service providers now offer programs to help people find alternatives to nursing homes or other institutional care. That’s up from less than a third in 2008, the survey said.

The increased focus on seeking alternatives to institutional care comes as the United States undergoes a dramatic demographic shift toward an older population. One response has been the rise of grass-roots efforts to create supportive communities, such as “villages,” designed to meet the daily needs of older people.

The survey of 618 agencies also found that their role has expanded to meet the federal Affordable Care Act’s goal of reducing the nation’s medical expenses by minimizing repeat hospital admissions. The survey, which was released Wednesday, suggests that the agencies have become key players in the ACA’s Care Transitions Program, which is designed to reduce costs by improving follow-up care for Medicare beneficiaries after their discharge from the hospital.

Local aging agencies, increasingly in partnership with private health-care companies and managed-care providers, now devote more efforts to ensuring that those patients remain healthy after returning home. Their intervention might be as simple as inspecting the homes of people who have been hospitalized for repeated falls to remove hazards.

“We’re seeing hospital readmissions being of high priority,” said Mary Kaschak, a senior program manager at the association who led the survey. “One, it’s a huge expense. And two, consumers and patients don’t want to go into the hospital continuously. So what Area Agencies on Aging are doing is providing that support at home.”

The survey also found that the agencies now serve a broader population than ever, including offering services for veterans and people under 60 who are disabled or chronically ill.

Area Agencies on Aging are part of a nationwide network of providers set up by the Older Americans Act, a landmark law enacted in 1965 to provide financing for a range of services for the elderly.