SPOILERS AHEAD! So after Sunday’s episode of The Walking Dead, episode 905, Scott Gimple announced on Talking Dead that there will be three The Walking Dead movies and one will definitely continue Rick Grimes’s story. I’m not sure about the other two movies. Below are more quotes about what we can expect in the future concerning the future movies.

In an AMC blog post, we find out that the first The Walking Dead movie will continue Rick’s story.

The first film will explore the story of where Rick is taken and what he faces in a new corner of the zombie apocalypse.
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We’re starting with the first part of the continuing story of Rick Grimes, and there is much more on the way, featuring yet-unseen worlds of The Walking Dead and faces from the show’s past, as well as new characters we hope to become favorites, told by TWD veterans and emerging voices.
Source: AMC.com

In a HollywoodReporter.com blog post, we find out that production of the first The Walking Dead movie is set to begin in 2019; they will be creating new content with possibly past characters;

Andrew Lincoln — following his departure Sunday from the flagship series — will reprise his iconic role as Rick Grimes in a series of three big-budget, feature-length TV movies for AMC. Gimple is currently writing the first of the untitled series of telepics, with production set to begin in 2019.
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Over the next several years, we’re going to be doing specials, new series are quite a possibility, high-quality digital content, and then some content that defies description at the moment. We’re going to dig into the past and see old characters. We’re going to introduce new characters and new situations.”
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The movies will be AMC Studios Original Films, will likely air on AMC and, in success, a second party as the cabler looks for a partner to share the costs.
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Gimple’s vision stretches beyond that and includes introducing content with brand new characters, revisiting old fan-favorite and obscure ones and, maybe, spinning off others in shows that could run anywhere from 16-episode seasons to short-order miniseries.
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We want to tell different stories but in different corners of the world.
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Also on the table: telling earlier stories featuring the returns of fan-favorite characters who are no longer with the series.
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As for the movies, they will follow what happens to Rick after his experience in Sunday’s “What Comes After” episode, where foe-turned-friend Jadis (Pollyanna McIntosh) rescues a near-death Rick and accompanies him on a helicopter to an unseen new community, while his friends and family believe the former sheriff is dead. Gimple confirmed Lincoln will indeed be in all three AMC movies, which he says will explore the period between Rick’s helicopter rescue and the years-later time jump that was featured at the end of Sunday’s episode — and stretch beyond that period. Each movie will tell a complete story about Rick. “It is about who he is and who he’s going to be — and certainly how he deals with the situation he’s in,” Gimple says. “We know Rick Grimes; he would want to be home.”
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The first pic will be told from Rick’s point of view and explore what Gimple called the “vast mythology” behind the other mysterious community looking for “A or B”-type people.

Source: HollywoodReporter.com