And it pays off. “On average, people’s disability is cut in half,” Dr. Szanton said. “Their pain decreases. Their ability to bathe and dress improves. People stuck on the second floor of their houses for years can go on family trips.”

CAPABLE reduced Medicaid spending and could create Medicare savings as well. Participants reported that it helped them remain at home, made their homes safer and helped them care for themselves.

Elsewhere, users of assistive devices tell similar stories. “We all know someone who had an aunt or a mother who couldn’t get out of the tub or off the floor, and bad things happened,” said Wendl Kornfeld, 72, who lives in Manhattan with her 83-year-old husband.

They had grab bars installed in their two showers for roughly $120 total, “not a huge investment and worth it for peace of mind,” Ms. Kornfeld said.

In Mt. Kisco, N.Y., Joan Potter appreciates the apartment renovations her late husband oversaw 20 years ago. He used a wheelchair, so their bathroom had a roll-in shower with a hand-held shower head, a raised toilet and grab bars in key locations. Now that Ms. Potter, 88, has undergone two hip replacements, she said, “I’m so grateful I have all these things, because I’m not so agile myself anymore.”

Why don’t more seniors take advantage of such devices?

Some adaptations that help people remain at home, like outdoor ramps and stair glides, carry high price tags; basic bathroom devices, widely available in pharmacies and online, generally don’t. But cost can still present an obstacle.

“Medicare covers ‘durable medical equipment’ — hospital beds, wheelchairs, walkers,” said Tricia Neuman, who leads the Kaiser Family Foundation’s program on Medicare. “It doesn’t cover hand rails or grab bars, things used around the house.”