The first book in The Selection trilogy, The Selection, was published in 2012 by HarperTeen. Television rights for the trilogy were optioned by the CW Television Network and two pilots were filmed, but neither were picked up for a full series. In April 2015, movie rights for The Selection trilogy, The Selection were acquired by Warner Bros.

On 12 January 2012 a one-star review of Cass’ book, The Selection, was posted on the book reviewing site Goodreads, and on the reviewer’s blog. Later on the same day, Kiera Cass’ literary agent, Elana Roth, posted a series of derogatory tweets on the social networking site Twitter. In a conversation that Cass and Roth believed was private—but was, in fact, public—Roth called the reviewer names and both Roth and Cass discussed how best to bump the negative review down and boost positive reviews by manipulating the ranking system themselves. The controversy sparked an article by Publishers Weekly speaking out against this practice and raised an outcry from multiple reviewers, bloggers, and publications against the cyber-bullying of non-professional reviewers by authors and agents.

In May 2013, Cass announced that she would be working on an as-yet untitled series she refers to as 238 on social media, to be published by HarperCollins.

On 14 August 2014, Kiera Cass announced that The Selection series would be expanding into more books. First, The Elite, was published in 2013. “The One” followed. The Heir followed in 2015. Cass announced another book following The Heir, The Crown, which was released on 3 May 2016.

On 4 February 2015 The Guardian posted a review about Kiera Cass, saying, “”Cass makes it a suspenseful read with dramatic events and romantic moments and you never know what is coming up in the next chapter”.” On 24 October 2015, The Guardian added, “”The story is also excellent for gripping people who don’t generally enjoy reading”.”