An updated version of "25 or 6 to 4" was recorded for the 1986 album Chicago 18 with James Pankow listed as co-writer. With the new band member Jason Scheff on lead vocals, the single reached number 48 on the U.S. chart. This version was also used as the B-side for the band's next single in 1986, "Will You Still Love Me?".
The song appears as an on-disc track in the video game Rock Band 3 and has been made available as a download for the game/learning software Rocksmith 2014.
Speculation that the song's lyrics are drug related has been largely dismissed. Lamm himself says that the title is "just a reference to the time of day" and that "the song is about writing a song. It's not mystical." The time of day in reference is 3:35 AM (or 3:34 AM), which would then be 25 (or 26) minutes to 4 AM.