Canonical has announced that Ubuntu Linux 16.04 LTS has reached it's end of life and is now supported until April 2024 with Extended Security Maintenance (ESM) through Ubuntu Advantage.

Ubuntu 16.04 LTS transitions to Extended Security Maintenance (ESM)

Ubuntu 16.04 LTS ‘Xenial Xerus’ transitions into the extended security maintenance (ESM) support phase at the end of April 2021 from its standard, five-year maintenance window for Ubuntu long term support (LTS) releases. Xenial Xerus is still supported until April 2024 with Extended Security Maintenance (ESM) through Ubuntu Advantage for Infrastructure, and on the public cloud with Ubuntu Pro for AWS, Azure and Google Cloud. ESM is also available to personal users on up to three machines and Ubuntu members on 50 machines. Ubuntu 16.04 is a Common Criteria certified operating system, providing access to FIPS 140-2 certified cryptographic modules with a solid history of timely security fixes.

Ubuntu long term support (LTS) releases provide a stable, enterprise platform for development and production, with five years of guaranteed public maintenance available. Once the public Standard Security Maintenance window comes to a close, Ubuntu LTS releases have an additional three to five years of support (depending upon the release) through ESM, in addition to providing a built-in upgrade in-place path to the next LTS release.

Ubuntu 16.04 LTS transitions to Extended Security Maintenance (ESM) | Ubuntu