1997, Federal Bureau of Prisons, 0.21% of inmates were atheist[7]
The Federal Bureau of Prisons does have statistics on religious affiliations of inmates. The following are total number of inmates per religion category:[8]
Catholic 29267 39.164%
Protestant 26162 35.008%
Muslim 5435 7.273%
American Indian 2408 3.222%
Nation 1734 2.320%
Rasta 1485 1.987%
Jewish 1325 1.773%
Church of Christ 1303 1.744%
Pentecostal 1093 1.463%
Moorish 1066 1.426%
Buddhist 882 1.180%
Jehovah Witness 665 0.890%
Adventist 621 0.831%
Orthodox 375 0.502%
Mormon 298 0.399%
Scientology 190 0.254%
Atheist 156 0.209%
Hindu 119 0.159%
Santeria 117 0.157%
Sikh 14 0.019%
Bahai 9 0.012%
Krishna 7 0.009%