Deborah Braswell, a university administrator in Alabama, is a member of a dwindling group — people with a landline phone at home.

According to a government study released Thursday, 50.8 percent of homes and apartments had only cell phone service in the latter half of 2016, the first time such households attained a majority in the survey. Braswell and her family are part of the 45.9 percent that still have landlines. The remaining households have no phones at all.

More than 39 percent of U.S. households — including Braswell’s — have both landline and cell phone service. The landline comes in handy when someone misplaces one of the seven cell phones kicking around her three-story house in a Birmingham suburb. “You walk around your house calling yourself to find it,” she said.

It’s also useful when someone breaks or loses a cell phone and has to wait for a replacement.

Renters and younger adults are more likely to have just a cell phone, which researchers attribute to their mobility and comfort with newer technology.

The in-person survey of 19,956 households was part of the Centers for Disease Control and Prevention’s National Health Interview Survey, which tracks landline use to assure representative samples in ongoing health studies. The survey has a margin of error of plus or minus one percentage point.

Cell phone-only homes have other common traits. “Wireless-only adults are more likely to drink heavily, more likely to smoke and be uninsured,” even after factoring for age and income, said Stephen Blumberg, the study’s co-author (and a landline user himself). “There certainly is something about giving up a landline that appeals to the same people who may engage in risky behavior.”

Why that is so will require further research.

The survey doesn’t get into why people ditch or keep landlines, though landline users cited a number of reasons for hanging on in phone interviews and email exchanges with the Associated Press.

Plenty of people would get rid of their landlines if they could. It goes beyond complaints about cellular reception at home.

Joe Krkoska, a supply chain director, needs a traditional copper wire for his home security system in Zionsville, Ind. Getting rid of the line would require crews to drill holes in his home and put batteries in the bedroom. No thanks, he said.

Chris Houchens, who works in sales and marketing, said his phone company forces him to get a landline with Internet service. There’s no cable TV alternative where he lives in rural Smiths Grove, Ky.

And those who could drop phone service might pay more after losing package discounts. Martin Axel, a retired hospital administrator in Seal Beach (Orange County), said dropping the landline would increase his cable bill by more than $40 a month.

Traditional phone lines have their own power supply, so they still work during blackouts. Internet phones through the cable or phone company aren’t true landlines, although the CDC counts them that way. The modem for these phones still needs power.

Both kinds of landlines are more dependable for 911. Even if you can’t give dispatchers your home address, they would often have that already. Cell phones primarily use GPS for location, which means the dispatcher might know which building you’re in, but not the specific apartment.

For that reason, Trey Forgety of the nonprofit National Emergency Number Association recommends landlines for those who live alone and have a disability or medical condition. He says cell phone location accuracy is improving, but there’s still work to be done.

One big problem with landlines: They’re a magnet for telemarketers.

“We never use the landline, and the only calls I get on it are from someone looking to sell me something,” said Matt Lawrence, a management consultant in O’Fallon, Mo.

On the other hand, it’s comforting to have a device just for calls — without “all of the irritating bells and whistles of smartphones,” said Brad Cooney, a Navy veteran in Brandon, Miss. “I can shut the (cell) phone off and still have a landline if someone needs to call me.”

The landline harks to an era in which a number is tied to a family and not an individual. You can call your parents’ home and not play favorites in choosing Mom or Dad. Children can talk to Grandma at once from separate phone extensions.

“My parents had landlines, as did their parents,” said Axel, the landline user in Seal Beach. “It’s probably a habit. It just feels more comfortable to me.”

Cynthia Dibblee, a retired teacher in Merced, said her parents “can’t remember our cell numbers, but know the landline by heart.”

USTelecom, a trade group for traditional phone companies, estimates that true landlines — the copper kind — now connect fewer than 20 percent of households. The group says companies have adapted by offering other types of services, including video and, for some, cell phones.

Even so, phone companies get new landline customers now and then.

Shawn Fisch, a 37-year-old teacher in New York, got his first landline after becoming a dad. When his son is old enough, he said, he’ll need “an extra way to phone home.”

Anick Jesdanun is an Associated Press writer.