CBS has renewed “NCIS” for two more seasons, which will keep the show on air through Seasons 14 and 15, the network announced Monday.

The renewal comes on the heels of executive producer and star Mark Harmon signing a new two-year overall deal. The renewal will keep the show on CBS through 2018, with no word yet on whether plans are in place for the show to end after Season 15 or continue.

“It’s extraordinary that in its 13th season and with over 300 episodes to its credit, ‘NCIS’ continues to excel at such a high level on a global scale,” said Glenn Geller, President, CBS Entertainment. “It is testimony to an amazing cast, led on and off the screen by the exceptional Mark Harmon, for skillfully bringing this universally appealing team of heroes to life; and to Gary Glasberg and his writers for crafting compelling stories that feature ‘NCIS’s’ signature blend of mystery, quirk, drama and comedy every single week.”

“NCIS” is the top rated broadcast drama in the U.S., averaging 20.47 million viewers in its 13th season. For the past two years, the show has been awarded the International Audience Award by Eurodata TV Worldwide and The Monte Carlo Television Festival for being “the most watched drama series in the world.” The show currently airs Tuesdays at 8 p.m. on CBS, having spawned two successful spinoffs, “NCIS: Los Angeles” and “NCIS: New Orleans.”

While Harmon will remain with the show for at least two more seasons, “NCIS” will bid farewell to star Michael Weatherly after the conclusion of Season 13. Along with Harmon, Pauley Perrette and David McCallum, Weatherly has starred in the drama since it premiered. His exit follows the departure of co-star Cote de Pablo, who left after Season 11. Sean Murray, Brian Dietzen, Rocky Carroll and Emily Wickersham round out the cast.

Harmon is repped by Paradigm and Barry Axelrod.