Apple says that it has determined that some iPhone 6 and 6s devices may not power on due to a component failure, and the issue affects a "limited serial number range," according to Apple. All affected devices were built between October 2018 and August of 2019. Owners of an iPhone 6 or 6s device that won't power-up can see if they have a device in an impacted serial number range by checking here.
Apple is clear that no other iPhone models are covered under the service program. If a device that fails to power on is in the serial number range to be covered, users have a few options to get their device repaired. Covered devices can be taken to an Apple Authorized Service Provider, owners can make an appointment at an Apple Retail Store, or they can also contact Apple Support to arrange for mail-in service.
As with most iPhone repair programs, if there is any damage to the device that would prevent Apple from fixing it, like a cracked screen, the damage will be repaired before the power issue is addressed. There could be cost associated with the additional repair, but there is no cost associated with repairing the power component failure.
Apple says that users who own one of the impacted devices, but paid out-of-pocket for the repair can contact it here to get a refund. Devices are covered under this program for the first two years after the initial retail sale of the device. Back in 2016, iPhone 6s devices had a battery component failure that caused some to unexpectedly shutdown.