An infant traveling under the Delta infant policy may travel free on an adult's lap in the United States and at a discounted fare on international flights if the child is under two. Parents may purchase a separate seat for the infant aboard an aircraft outfitted with an FAA-approved child restraint system. Delta Air Lines may check in one stroller and car seat for free. Infants in laps must be in the reservation. Infants must be ticketed on specific international routes, and taxes and fees may apply.