Blog · Legacy systems
SQL Server 2016 went out of support in July. Windows Server 2016 follows on January 12
Microsoft ended extended support for SQL Server 2016 on July 15, 2026, and extended support for Windows Server 2016 ends on January 12, 2027. After those dates, security fixes come only through the Extended Security Updates (ESU) program, which is paid outside Azure. Everything keeps working the next day; what changes is who pays to stay secure.
What Microsoft says about each product
For SQL Server 2016, the lifecycle page lists the end of extended support as July 15, 2026, the same day Service Pack 3 went out of support. Below that, it lists three years of ESU: the first runs from July 15, 2026, to July 13, 2027, and the third ends on July 17, 2029.
Windows Server 2016 is on the list of products whose support ends on January 12, 2027, along with Hyper-V Server 2016, IIS 10 on Windows Server 2016 and .NET Framework 4.6.2. Microsoft's Extended Security Updates page says ESUs for Windows Server 2016 start that same day.
For products that reach end of support, Microsoft states that there are no more security updates, no other fixes and no technical assistance, free or paid.
What ESUs cover and what they don't
According to Microsoft's FAQ, ESUs are a paid, last-resort option, meant as a temporary bridge while you migrate. They include only critical or important security updates, for up to three years after the end of extended support. They add no new features, bring no non-security fixes and include no technical support.
Outside Azure, you buy them through volume licensing or through Azure Arc; for Windows Server, they require active Software Assurance or subscription licenses. On Azure virtual machines, they come at no additional cost.
Why it pays to decide before the deadline
An unpatched server doesn't go down: it keeps serving users while it piles up known vulnerabilities. ESUs buy time, but they have a cost and an end date. The underlying work stays the same: know what runs on those versions, test it on a supported version and migrate.