Before Letterman's arrival, CBS' New York flagship, WCBS-TV, specifically used the Late Show name for its late-night movie programming.

When David Letterman became available after being passed over by NBC for The Tonight Show, CBS was eager to lure him and offered him a three-year, $14 million per year contract,[2] doubling his Late Night salary.

[3] CBS' total cost for acquiring the show—including renovations, negotiation right paid to NBC, signing Letterman, announcer Bill Wendell, band leader Paul Shaffer, and the rest of the band—was over $140 million.

Letterman renamed a few of his regular bits to avoid legal problems over trademark infringement (NBC cited that what he did on Late Night was "intellectual property" of the network, a contention he disputed).

"Viewer Mail" on NBC became the "CBS Mailbag", and Larry "Bud" Melman began to use his real name, Calvert DeForest.

CBS inaugurated the summer format with reruns of the final season of The Mentalist, a cancelled prime time police procedural, airing nightly from May 21 until June 5, 2015.

[16] Colbert's version retains the Late Show name under license from Letterman's Worldwide Pants, which holds the registered trademark.

[19] A deal to keep the show at the Ed Sullivan Theater, which includes $16,000,000 in state tax incentives over a five-year period, was made official on July 23, 2014.