Meanwhile, one in 10 Americans are currently using a dial-up connection and many do not intend to upgrade to broadband.
Nearly two-thirds of dial-up users have no interest in switching to faster broadband connections, most citing cost or convenience. The majority of these are women living in rural areas.
More worryingly, over a quarter of Americans have no internet access at home, the majority of whom are either elderly or on low incomes.
"Although these demographic and socio-economic factors are powerful forces keeping some people off the net, many non-users are not completely disconnected from cyber-space," said the report.
"Some 21 per cent of non-users said that someone in their household uses the internet at home, and a fifth of current non-users have used the internet at some time in the past."
However, a third of non-connected households reported that they have no interest in using the internet at all.