The Pew Research Center's Internet & American Life Project said smartphone adoption has jumped from 35 per cent in 2011 to 56 per cent this year.
The survey, which polled more than 2,200 adults in April and May, found 91 per cent owned some kind of mobile phone, and a majority said that phone was s smartphone or operated on a smartphone platform.
Some 35 per cent said they have some other kind of cell phone that is not a smartphone, and the remaining nine per cent did not own a cell phone at all, the survey found.
But every major demographic group boosted smartphone ownership between 2012 and 2013: some 69 per cent of those aged 35 to 44 had a smartphone as did 55 per cent of those 45 to 54.
Also Read
Among those over 65 year old, 18 per cent had smartphones.
"Younger adults -- regardless of income level -- are very likely to be smartphone owners," the report said.
"Conversely, for older adults smartphone ownership is more of an 'elite' phenomenon: smartphones tend to be quite prevalent at the upper end of the income distribution but much less common among those with lower income levels."
The wealthier and more educated were more likely to report using a iPhone -- 49 per cent of cell owners with a household income of USD 150,000 or more said that their phone is an iPhone.
The report was in line with surveys from market research firms.
According to a recent Kantar Worldpanel ComTech survey, Android, the free operating system from Google, remained the top platform with 51.7 per cent of US sales to 41 per cent for Apple's iOS.