* The Heroes of Olympus series: While not exclusively about Percy, he is a prominent character throughout the five-book series, which picks up a few years after *The Last Olympian*. This series features new characters and storylines while also delving deeper into Percy's relationships and development.
* The Trials of Apollo series: Percy makes a brief but important cameo appearance in *The Hidden Oracle*, the first book of this series. It's a fun surprise for fans, though his role isn't extensive.
* Percy Jackson and the Olympians: The Graphic Novel Series: These adaptations of the original five books, while not providing new material, are a great way to revisit Percy's adventures in a new visual format.
* Rick Riordan's website and social media: Rick Riordan sometimes shares updates and behind-the-scenes information about his books, including tidbits about Percy. He has also expressed interest in exploring Percy's story further in the future.
So, while there isn't a standalone Percy Jackson book after *The Last Olympian*, there are several ways to experience more of his journey and adventures within the larger world of Rick Riordan's books.