Tech Insights has published an in-depth iPhone 18 Pro Max teardown confirming the United States variant uses a Qualcomm Snapdragon X80 modem, not Apple's in-house C2. While Apple's tech specs list the C2 for the iPhone 18 Pro and iPhone 18 Pro Max in every other country, the U.S. iPhone 18 Pro Max specification was unspecified. The teardown reveals it matches the modem used globally in the iPhone 17 Pro and iPhone 17 Pro Max.

Apple's modem transition in the U.S. has been staggered: iPhone 16 series used Qualcomm Snapdragon X71, iPhone 16e debuted the Apple C1, iPhone 17 series used Qualcomm X80, iPhone Air and iPhone 17e use Apple C1X, iPhone 18 Pro uses Apple C2, and iPhone Duo uses Apple C2. The C2 adds mmWave 5G support and claims 15% better energy efficiency versus C1X.

Apple hasn't explained why the iPhone 18 Pro Max retains Qualcomm in the U.S., but contractual obligations are the likely cause. The C2 now matches Qualcomm's mmWave capability while maintaining Apple's power-efficiency advantage.