Open Jaw
Imagine you want to spend two weeks in Europe, flying into Paris and ending your trip in Rome. Booking a round-trip to Paris and then purchasing a separate one-way from Rome back to New York in cash could cost several hundred dollars for that final transatlantic leg alone. An open-jaw award ticket, such as JFK to CDG outbound and FCO to JFK on the return, solves that problem by treating the surface segment between Paris and Rome as an assumed connection you handle independently. The award price at most programs stays the same as a standard round-trip within the same region pair, so the "free" positioning is baked in.
A common point of confusion is treating open-jaw and stopover as interchangeable terms. They are not. A stopover is a deliberate pause at an intermediate city on the itinerary, often for 24 hours or more, where you actually have a ticketed flight continuing onward. An open-jaw has a gap in the routing, a surface segment, where no flight is issued at all. Some readers also confuse open-jaw with a one-way award or a multi-city booking; the key distinction is that an open-jaw still prices as a round-trip under most programs' award charts, while true multi-city itineraries can trigger separate one-way pricing.
Most programs restrict open-jaws to the same geographic region for the surface segment. A United MileagePlus award, for example, generally allows the open city and the origin or destination city to sit within the same region without adding a zone to the pricing calculation. Alaska Mileage Plan is a notable exception: it permits trans-regional open-jaws, meaning the gap between the open cities can cross regional boundaries while the ticket still prices as a round-trip, which is one reason Alaska's program earns attention in our sweet spots guide. Rules and region definitions vary by program, so always verify the specific carrier's award chart before building the routing. For programs that price by distance rather than zone, the surface segment may or may not count toward the total mileage calculation depending on the carrier's rules.
Build the open-jaw routing in the search tool before committing any points transfer, because award calendar availability for your specific city pairs is what actually controls whether this strategy works.