18 Again! (1988) is a Fantasy, Comedy film that follows 81-year-old millionaire Jack Watson switches bodies with his 18-year-old grandson David, leading the two to experience life on opposite ends of the age spectrum. But when David, trapped in Jack's aged body, ends up in a coma, his grandfather must use his meager knowledge of the youth to prevent his family from pulling the plug. Currently, you can watch 18 Again! on Amazon Prime Video, Amazon Prime Video with Ads, Amazon Video. Streaming availability may vary by country and platform over time. It has a user rating of 5.6 out of 10 from 97 votes. Fans of fantasy movies may also want to explore similar titles below.