For the MacBook Pros, the only models you can upgrade are older releases, starting with the very first 15-inch MacBook Pro from early 2008 up to the 13-inch and 15-inch MacBook Pro from mid-2012.

The RAM upgrade to bring the entry-level 13-inch MacBook Pro to 16GB from 8GB is just one of the many options available to customers upon checkout of the laptop on Apple’s online store.

For the Mac Pro, you can only upgrade the RAM of the variants from 2006 to 2019 (both base and rack models). ... The 13-inch MacBook Pro from 2012 also features similar RAM type and speed, ...

While practically all PC laptops enable the user to upgrade RAM, some MacBook models do not. As of July 2013, current MacBook Air and Retina Display MacBook Pro models cannot be upgraded after ...