I was browsing the FFRF site and ran across an article referencing Barney Frank coming out as a secularist last month on Real Time with Bill Maher. Frank is no longer in office.
This got me curious enough to see if any sitting members of Congress are "out" as atheists. It seems there is just one: Rep. Pete Stark (D) CA. Besides Rep. Stark, 10 members of Congress "unspecified, don’t know, or refused to answer”. I find that rather interesting.