The number of U.S. homes with only cellphones is growing, with 41 percent of them without landlines in the second half of 2013, the Centers for Disease Control and Prevention said on Tuesday.
The increase in cellphone-only households is slowing, the CDC report said, and those without landlines tend to be younger, poorer, renters and Hispanic.
The percentage of Americans in homes without landline phones in the second half of last year was up 2.8 percentage points from the second half of 2012.
That marks a slowdown in the annual increases from the second half of 2010 to the second half of 2012, which were just over 4 percentage points.
Households are identified as "wireless-only" if they include at least one wireless family and if there are no families with landline phone service in the household.
The CDC numbers are based on the National Health Interview Survey, carried out throughout the year to collect information about health status and healthcare.
The CDC interviewed 21,512 households in the second half of last year. The survey has asked whether a home had a landline phone since 2003 as part of an effort to improve the accuracy of CDC health estimates.
Nearly two-thirds of people ages 25 to 29 lived in households with only wireless phones, with majorities for those 18 to 24 and 30 to 34, the survey showed.
Three in four adults living only with unrelated adult roommates were in wireless-only households and 61.7 percent of adults in rented homes were without landline service.
Fifty-six percent of people living in poverty had only wireless phones and 53 percent of Hispanics had only cellular phones.
The CDC also found that wireless-only adults were more likely to have five or more alcoholic drinks in a day and more likely to be smokers. They also are more likely to be without insurance coverage, have had financial trouble getting healthcare and to have been tested for HIV, the virus that causes AIDS.