Apple launched their iPhone 5C back in September 2013 and Apple has now added the smartphone to their vintage device list.
What this means it that the handset will now have limited technical support, this is something Apple does with older models.
Vintage products are those that have not been sold for more than 5 and less than 7 years ago. Mac, iPhone, iPad, iPod, and Apple TV vintage products continue to receive hardware service from Apple service providers, including Apple Retail Stores, subject to availability of inventory, or as required by law.
Apple does a pretty good job of supporting its devices, the handset is now seven years old, not many smartphone manufacturers provide full support for their smartphones for this long. The iPhone 5C will be made obsolete in 2022, which will end technical support for the device.
Source 9 to 5 Mac