Delta SkyMiles vs United MileagePlus 2026: Which Loyalty Program Wins?

United MileagePlus is the better loyalty program for international redemptions in 2026 — Star Alliance partnerships let you book seats on Lufthansa, ANA, Singapore Airlines, and Swiss at fixed partner award rates that still provide genuine value. Delta SkyMiles is the better program for domestic US travel, especially if you're based near a Delta hub — its dynamic pricing model produces good off-peak domestic rates, and Medallion status perks (complimentary upgrades, priority boarding, waived fees) are competitive. For casual travelers who don't optimize award bookings, Delta's superior domestic reliability makes SkyMiles the practical default. For travelers who specifically want premium international redemptions, MileagePlus offers more flexibility.