Ubuntu 16.04 LTS was released in April 21, 2016. It had many updates since the time it was released, with the latest point release racking up to 16.04.7 in August 10, 2020. You can see the release information in the links found on this page.
So, Ubuntu 16.04 LTS will reach end of support somewhere in April 2021. We are very close to that moment as Ubuntu 21.04 Hirsute Hippo releases. While you can still use it due to it having an ESM that lasts until April 2024, it’s recommended that you upgrade.
We recommend upgrading to Ubuntu 20.04 LTS if you still use 16.04 LTS. Here’s what will happen once 16.04 LTS ends its standard support:
- You still can download this version of Ubuntu and its flavors from cdimage.ubuntu.com until ESM ends
- You can’t get any kind of support, including IRC (#ubuntu @ freenode)
- Many software distributors will stop supporting this version. For example, we’ll stop shipping new versions of our software like KS starting from version 0.0.16.0.
- You can’t get security updates for all the packages, especially openssl.
- You can’t get new updates for existing packages.
- You can’t get new packages for this version of Ubuntu.
To upgrade your system, either use System Updater by opening the Dash and writing “update,” or use the terminal to execute this command as root:
# do-release-upgrade
If you don’t have access to root, you can append sudo prior to this command so it looks like this:
$ sudo do-release-upgrade
If you can stand upgrading to new version of Ubuntu every 6 months, such as 21.04, you can go ahead, but we recommend upgrading to the latest LTS version.
Stay home and wear your masks.
Aptivi 
Thoughts?