The former House speaker, who is putting a campaign organization together on the fly, failed to qualify for the contest in the Show Me State.
The filing requirements are not particularly onerous. A $1,000 check and some paperwork are all that's needed.
Missouri's primary is a "beauty contest," meaning that no delegates will be awarded. The state Republican Party will hold caucuses in March for that purpose.
However, Missouri is a major state, and the nonbinding contest will be the only primary in the country between the Florida primary on Jan. 31 and the Arizona and Michigan primaries on Feb. 28. Candidates wishing to maintain their momentum, and media visibility, through that dry spell in February may well see Missouri as a place to compete for bragging rights.
That's why Gingrich's will be the only familiar name missing from the GOP ballot. A total of 10 Republicans qualified, including the seven others joining Gingrich on stage in Tuesday night's CNN debate in Washington, and three minor candidates.