The official requirements
Engadget published Apple's complete hardware requirements for Siri AI: the feature will be available on iPhone 16 or later, iPhone 15 Pro and iPhone 15 Pro Max, iPad mini with A17 Pro chip, iPad with M1 or later, Mac with M1 or later, Apple Vision Pro, Apple Watch Series 10, Ultra 2, and SE3 — the latter only when paired with an Apple Intelligence-capable iPhone. TechRadar noted that the list is surprisingly short.
What is excluded
IPhone 15, iPhone 15 Plus, the entire iPhone 14 lineup, and earlier generations will not get Siri AI, even though iOS 27 will install on them. The cutoff corresponds broadly to the adoption of the A17 Pro chip and the M-series for iPad and Mac. Someone who bought an iPhone 15 base model in 2023 — a device just three years old — is excluded from the flagship feature of the new operating system.
More restrictive than base Apple Intelligence
It is important to distinguish: iOS 27 runs on iPhone 11 and later; base Apple Intelligence runs on a narrower subset; but Siri AI — the most prominently featured function — has even more selective requirements. This effectively creates three tiers of user experience: software update without AI, partial Apple Intelligence, and full Siri AI. A segmentation that nudges toward hardware upgrades, not just software ones.