19.99 is the third extended play (EP) by South Korean boy band BoyNextDoor, released on September 9, 2024, through KOZ Entertainment, five months following the preceding EP How? (2024). With members Jaehyun, Taesan, and Woonhak credited for writing the EP's tracks, 19.99 explores the anxieties of the youth before they turn twenty. The EP will be supported by two singles: "Dangerous" and "Nice Guy".