Like many older Americans, Shazzi Felstein recently found herself in an unexpected financial bind. About a year ago, she noticed that her savings had dwindled. To her horror, she realized that her monthly Social Security check would not cover her rent-stabilized one-bedroom apartment in Chelsea and monthly expenses like utilities and food for much longer.

A former computer systems analyst, Felstein, 73, had always saved as much as she could and had enjoyed relatively stable finances. That changed in 2011, she said, when she lost about $80,000 in retirement savings after investing in a company that turned out to be guilty of fraud.

The owners of the Massachusetts-based Inofin Inc., a subprime auto loan company, swindled hundreds of investors, and the company entered into involuntary bankruptcy. Felstein has been unable to recoup her money, although the company’s founders pleaded guilty to fraud and were sentenced to jail.

“I felt very lost,” Felstein said. “I have always paid my rent on time, and I knew if I didn’t do something, I wouldn’t be able to live here anymore.”

She thought about moving in with her sister in Florida, but knew it would put a strain on their relationship. A native New Yorker, Felstein has lived in the same apartment for almost 40 years and had no desire to move.

So she did what many others do to keep down costs in an expensive city: She found a roommate.

Instead of placing an ad online, Felstein turned to the New York Foundation for Senior Citizens, a Manhattan-based nonprofit. The group has been operating a home-sharing service since 1981, matching people who have space in their homes with those in need of affordable housing. It is one of a number of similar programs that have emerged across the country as the population of older Americans grows, as a way to help people stay in their homes.

Need to pair off

The concept of pairing older people with younger ones, particularly those who are not family members, is not a new one: It was popularized by Maggie Khun, an elder-rights activist who opened up her Philadelphia home to others for more than 20 years before she died in 1995. Today’s home sharing, however, is as likely to be between those of the same age as it is to be intergenerational. The crucial thing is that it involves two or more people sharing an apartment or a house to their mutual benefit. And finances often play a big role.

For those who are still working age, it’s getting harder to pay the rent: According to a StreetEasy survey, rents in the city rose twice as fast as wages between 2010 and 2017. The lowest rents (those up to $2,300) rose 4.9 percent annually since 2010, which means someone who paid $1,500 a month in 2010 likely paid nearly $600 more for the same place in 2017.

For baby boomers entering retirement, financial security is also increasingly hard to come by. Many Americans may think they have plenty of savings, but about half have not saved enough to maintain their pre-retirement living standards, according to a recent estimate by the Center for Retirement Research at Boston College. The rising cost of health care, increased life expectancy and lower interest rates only exacerbate the situation. In addition, a Fannie Mae survey found that baby boomers are more likely to be carrying mortgage debt into their retirement years than previous generations were.

To Felstein, who was confronting these realities, there didn’t seem to be any other option than taking in a roommate. The New York Foundation for Senior Citizens connected her with a licensed social worker who asked a host of questions, including details about her sleeping habits, personality, interests and daily schedule. She also had to provide three personal recommendations and her rental agreement, to prove she was on the lease.

And she was asked to describe what she considered the ideal roommate. Her response: someone who wasn’t home much.

“I knew it would be a long shot,” she said, “but I thought I should be honest.”

She found her match in Yukari Honda, a 27-year-old graduate student in interior design at the New School. Honda, who is from Tokyo, is often at school from morning until past midnight.

A year ago, Felstein moved out of her old bedroom to make room for Honda. She replaced the living room sofa with a bed, turning the living room into a bedroom for herself. Fortunately, there is a separate kitchen and common room where Honda studies and Felstein keeps reams of fabric for her quilting.

The two split the utilities and the $1,145 rent equally. They rarely share meals or do things together, but have found that they seek each other out in other ways. “Shazzi is so patient, she has helped me for hours with my schoolwork,” Honda said.

Felstein, an avid quilter, said she has been thrilled to talk about design and assist Honda with her assignments. In return, Honda has been helping out more with the housework.

“Getting a roommate at my age certainly required some mental adjustment,” Felstein said. “But it has been wonderful in so many ways.”

Wendi Burkhardt, chief executive of Silvernest, an online home-sharing and roommate-matching service geared toward older adults, thinks society’s penchant for independent living has clouded the conversation about how we age.

“I really think ‘The Golden Girls’ were early trendsetters,” she said, referring to the popular TV sitcom from the late ’80s and early ’90s, in which four older women lived under the same roof in Miami. “Why wouldn’t you want to share your home with others, whether it’s for financial reasons or for companionship?”

Services to find roommates

Although placing an ad and setting up a profile is free, Silvernest charges those who have rooms to rent about $30 to use the messaging service to communicate with potential roommates. Those seeking rooms pay the same amount, which covers a background check and gives them access to the listings.

Sarah Oswald, a relationship coach who lives in Boulder, Colorado, said she messaged numerous people through Silvernest to find her father, John Oswald, a roommate.

John Oswald, 69, lives in a one-bedroom rent-stabilized apartment in the West Village and has no pension to rely on, he said, because he worked in the nonprofit world for years. Health issues stemming from his service in the Vietnam War also took a toll on his finances, because numerous surgeries on his legs prevented him from working at times.

Sarah Oswald said she tried using Craigslist and university housing boards, but they were difficult to navigate from afar. With Silvernest, she said, she was able to carefully read all the profiles, which made choosing whom to message and to introduce to her father much simpler. “The vetting the firm does for you helps,” she said.

Other startups are following suit. Nesterly, an online portal that matches intergenerational roommates, will start offering services in New York this year after being introduced in Boston last fall. “We’d like to help create new units of affordable housing at a time when there’s a dire need for it,” said Noelle Marcus, a founder.

Finding the right match

Elizabeth Rosania, 86, learned a painful lesson when she found boarders through the classifieds in the local paper. After her husband died in 2013, a year of living alone in her four-bedroom, three-bathroom house on a 4-acre estate in Lebanon, New Jersey, left Rosania lonely and seeking company.

She had worked as a nurse her entire life, she said, and she wanted to continue helping people in another capacity. Her first few tenants, however, were too much for her to handle. One female tenant in her 70s was addicted to OxyContin. Another tenant, a struggling alcoholic in her 50s, stole a 9-foot satellite dish, jewelry and appliances, Rosania said.

But last year, she found John Costanzo, 61, with help from social workers at HomeSharing Inc., a nonprofit in Bridgewater, New Jersey, and the two became fast friends. They now watch TV, run errands and eat most meals together.

For Costanzo, a former Marine who owned a crane-rigging business and is on disability after several back surgeries, affordable housing was essential. He pays $600 for his room, a monthly fee that includes utilities and cable. He is not allowed overnight guests, alcohol and drugs are prohibited in the house, and he must keep the bathroom clean at all times.

Melissa McHam Green, a licensed social worker and elder-care manager in Brooklyn, has helped some of her clients find roommates and agree on mutually beneficial guidelines. She advises those interested in home sharing not to go about it on their own: Go through a nonprofit service, she said, or ask a trusted elder-care professional, friends or family to help properly vet the prospective roommates. And before you sign a lease with a boarder, make sure to do a background check.

“You need a huge amount of trust and to be very clear with your expectations,” she said.

“But if you have the help you need to stay in your home — and the tenant gains affordable housing in exchange — I think there’s much to gain socially and spiritually when young and old live together.”