Brody Shelton, 21, was last seen around noon Thursday near Laporte Street and Johnston Street in Highland, Indiana, officials said.
Indiana State Police have issued a Silver Alert as the the search for Shelton continues.
He is 5 feet 2 inches tall, 155 pounds, brown hair with brown eyes, and was last seen wearing a beige and green sweatshirt, and riding a blue/green Huffy mountain bike, police said.
Anyone with information has been asked to contact the Highland Police Department at 219-838-3184 or 911.