Amazon ElastiCache for Memcached adds support for the latest Memcached open source version 1.5.16. This is a bug fix release with various improvements in stability and includes the fixes from engine versions 1.5.14 and 1.5.15.
For the full list of improvements in Amazon ElastiCache for Memcached 1.5.16 click here. Memcached 1.5.16 support is available in all AWS regions.
To get started on ElastiCache for Memcached cluster with engine version 1.5.16 log on to AWS Management Console.
from Recent Announcements https://aws.amazon.com/about-aws/whats-new/2019/09/elasticache_memcached_1_5_16_available/