Windows Server 2016 End of Support: What to Do Before January

Extended support for Windows Server 2016 ends on January 12, 2027. After that date, servers still running it stop receiving regular security updates unless they're enrolled in Extended Security Updates (ESU). For most teams, that date lands right after the holiday change freeze.

This post sets out the dates Microsoft publishes, how ESU for Windows Server 2016 works, and the upgrade and migration paths Microsoft documents, so you can decide what each server needs before January.

The Dates Microsoft Publishes

According to Microsoft's Windows Server 2016 lifecycle page and its Azure Arc ESU guidance:

• Mainstream support ended on January 11, 2022.
• Extended support ends on January 12, 2027. This covers the Datacenter, Essentials, MultiPoint Premium and Standard editions, and containers released with Windows Server 2016.
• ESU provides Critical and Important security updates for up to three years, through 2030.
• ESU enrollment through Azure Arc opened in the Azure portal on August 3, 2026, and billing begins January 13, 2027.

ESU doesn't add features, customer-requested non-security fixes or design changes. It keeps a server patched while you move it.

Getting ESU Through Azure Arc

Microsoft announced ESU for Windows Server 2016 in February 2026 and delivers it through Azure Arc for on-premises and multicloud servers. What Microsoft's guidance says:

• Connect each server to Arc first. Windows Server 2016 ESU needs the Azure Connected Machine agent version 1.62 or later. Standard and Datacenter editions are supported.
• Monthly, pay-as-you-go, billed through Azure. You can draw down an existing Azure consumption commitment. Reducing or removing a license keeps billing for up to five calendar days.
• No product keys. Enrollment is keyless, and the Azure portal shows which Arc-enabled servers are covered.
• Late enrollment is back-billed. Billing begins January 13, 2027, and licenses provisioned later are back-billed to January 12, 2027, so waiting doesn't save money.
• Azure VMware Solution and Azure Local VMs are different. Microsoft's Arc guidance lists them as eligible for free ESUs, and they shouldn't enroll through Arc.

Sizing Windows Server 2016 ESU through Azure Arc: five rules

• Physical cores: minimum of 16 per machine. Standard covers up to two VMs; Datacenter covers unlimited VMs.
• Virtual cores: minimum of eight per VM, always licensed as Standard, and not usable on physical servers.
• No free DR or dev/test cover for 2016: the no-cost disaster recovery and Visual Studio dev/test benefits aren't available for Windows Server 2016 ESUs.
• Licenses are adjustable, not automatic: you set edition and cores when creating the license and pick the core type when enabling servers. Core counts can change later, but billing doesn't drop on its own.
• Licensing: Software Assurance, a server subscription, or SPLA is required.

For eligibility, sizing and a full enrollment checklist, see our guide to Windows Server 2016 ESU through Azure Arc.

On price, Microsoft's March 2026 pricing update says ESU offerings released on or after April 1, 2026 carry the same list price whether the workload runs in Azure, on-premises or in another cloud. Get the price for your agreement from your licensing partner.

The Paths Microsoft Documents

For servers you keep, Microsoft documents three routes:

1. Upgrade in place. Starting with Windows Server 2025, non-clustered in-place upgrades can skip up to four versions, so a Windows Server 2016 server can go straight to Windows Server 2025. Check the application's support statement for the new version first.
2. Build new and migrate. Stand up a server on a supported version and move the roles, applications and data across. It takes longer, but it's the cleaner option for servers with years of accumulated configuration.
3. Move the workload to Azure. Re-platform or rehost it, then upgrade there. Our guide to Azure Migrate readiness checks covers the assessment side.

ESU fits alongside all three. It's the right choice for the servers that genuinely can't move before January, as long as each one has a date to leave it.

Check What Runs on Top

Windows Server 2016 often hosts other software that's already past its own end of support. SQL Server 2016 left extended support on July 14, 2026; our post on SQL Server 2016 end of support covers its options. And if any Windows Server 2012 or 2012 R2 servers are still around, their final ESU year ended on October 13, 2026, as our Windows Server 2012 R2 post explains.

A Short Plan Before January 12

1. Count the servers. List every Windows Server 2016 machine, physical and virtual, with its edition, core count and owner.
2. Decide per server. Upgrade in place, rebuild, move to Azure, retire, or cover with ESU for a fixed period.
3. Connect the ESU group to Azure Arc now. Enrollment is already open, and getting agents deployed before the change freeze avoids a scramble in January.
4. Give every ESU server an exit date. ESU buys time, and the time costs money every month.

Most environments don't need a large program for this. They need an accurate server list, a decision for each server, and the ESU group connected to Arc before January 12.

Book a Windows Server review. We'll help you count what's left, plan the upgrades, and set up ESU for the servers that need more time.