SQL Server 2016 end of support

The instance keeps working — nothing breaks on the day, which is what makes this easy to defer. What stops is security updates, so any vulnerability disclosed after 15 July 2026 remains unpatched. You also lose access to Microsoft support cases, and you will fail patch-currency expectations under the ACSC Essential Eight and most enterprise supply-chain reviews.

It depends on the application, not the database. Upgrading in place is usually cheapest over three years and keeps everything familiar. Azure SQL Managed Instance removes the upgrade treadmill permanently because Microsoft patches the platform, but needs the application to tolerate a small set of T-SQL differences. We test compatibility before recommending either.

ESUs are paid security patches that continue after extended support ends — up to three years, with Year 3 running to 17 July 2029. They are a bridge, not a destination: cost rises each year and the version keeps ageing. Sensible when a migration is genuinely planned and dated; expensive when used to avoid making a decision. Confirm current pricing and eligibility with your licensing partner.

The database migration itself is usually a single change window. The work is the compatibility testing before it — that is where the time goes and where failed upgrades fail. We assess the estate, test against a restored copy, and plan a rollback before touching production.

Near-zero downtime is achievable with Always On availability groups or log shipping, moving the workload to the upgraded instance and cutting over. Whether it is worth the additional complexity depends on what an hour of downtime actually costs you — we will tell you honestly when it is not.