While we don't yet know the new iPhones Apple will be dropping this fall — though there are iPhone 17 rumors — we do know, per Apple's site, that the phones listed below will be compatible with iOS 26. Basically, if you have an iPhone that was announced in 2019 or later, you're in the clear:

Apple has officially released the public beta of iOS 26, giving iPhone users a chance to experience the next-generation software ahead of its final rollout. The update brings a bold new design, Apple Intelligence features, and improvements across core apps and services.