OnePlus has been updating its smartphones to OxygenOS 16 based on Android 16 for quite a while now, and it's finally reached lower-midrange devices today.
The update is now available for the Nord CE4 and the Nord CE4 Lite, which were both released in 2024. The Nord CE4 is seeing the rollout commencing in India with the new software build being labeled CPH2613_16.0.2.400(EX01).

The Nord CE4 Lite's new build number is CPH2619_16.0.1.301(EX01). This too is only rolling out in India at the moment, with more territories supposedly to follow in the future.
As with any software update, the rollouts are staged, so it might take at least a few days, if not more, before all eligible phones get the notification. The updates come with the December 2025 security patch level.