The 2014 General Social Survey conducted by NORC and the University of Chicago said that while the number of Americans who said they believe in God held steady, the number who are abandoning specific religion at record numbers.
The study showed that 21 percent of Americans say they have no religion compared to just 5 percent in 1972.
The number was higher than a Gallup survey released earlier this year where 16 percent of surveyed Americans said they had no religion.
The GSS found that only 3 percent of respondents said there was no God. At least 58 percent said they have faith in God, 70 percent added they believe in life after death. Five percent of the survey identified as agnostic.
The younger generation showed the biggest increase in those without any religion. One-third of the adults under 30 said they have no religious affiliation.