SQL Server end of support: what extended security updates cost against a migration

The deadline is published, and it is different for each version

SQL Server 2016 extended support ends in July 2026, and its Extended Security Updates run from July 2026 to July 2027, July 2027 to July 2028 and July 2028 to July 2029. SQL Server 2014 ended in July 2024, with ESU years running to July 2027. The dates are fixed and Microsoft publishes them, so a team running both versions is managing two clocks, not one.

The ESU subscription protects servers for up to three years after the support lifecycle ends, and Microsoft describes it as something to keep until you are ready to upgrade to a newer version or migrate to Azure SQL. Coverage is continuous until cancelled, and the subscription cancels automatically when the instance is migrated to Azure or upgraded to a supported version.

There is no regular release cadence. Microsoft makes ESUs available if needed once a security vulnerability is discovered and rated Critical by the Microsoft Security Response Center, so the subscription buys critical patches and not a monthly patch Tuesday. That matters for a change board that plans around a cadence.

One operational step sits before the first ESU. If you only applied General Distribution Release updates during normal support, install and validate the latest Cumulative Update at the time you subscribe rather than waiting for the first ESU, because Microsoft warns that preemptive validation avoids problems when the ESU is installed later.

What the pricing change on 1 April 2026 does to the Azure route

Microsoft is introducing a consistent ESU pricing model so customers pay the same list price regardless of deployment location, whether Azure, on-premises or another public cloud, and regardless of purchasing channel across the Microsoft Customer Agreement, Enterprise Agreement, Cloud Solution Provider programme and other licensing programmes. The new model applies from April 1, 2026 for any new ESU offerings for Windows products and SQL Server.

The change does not apply to existing offerings, including ESUs for Windows Server 2012, Windows 10 version 22H2 or SQL Server 2014. So the SQL Server 2014 estate keeps whatever terms it already has, and the SQL Server 2016 estate is the one that meets the new model.

The other half of the change is narrower than it looks. Starting with SQL Server 2016, migrating the workload to SQL Server on Azure VMs no longer provides free access to ESUs. SQL Server 2014 customers still receive free ESUs when they migrate to Azure VMs, and also when they migrate to Azure VMware Solution. A team that learned the 2014 playbook and applies it to 2016 will find the free patches gone.

Microsoft's own framing is that the update builds on a principle of a consistent pricing model and reflects a commitment to transparency and alignment across deployment options and purchasing channels. For a buyer, the practical reading is that the Azure destination no longer prices differently for SQL Server 2016 ESUs, so the migration case has to stand on workload fit rather than on free patches.

The per-core number is not on the page, and that is the first thing to ask for

None of the Microsoft pages state a price per core for SQL Server ESUs. The licensing page describes the pricing model and the date it starts but publishes no figure, and the ESU documentation describes eligibility and delivery but no rate. A reader pricing a 64-core estate cannot get the number from the vendor's public documentation.

What the pages do establish is the shape of the bill. ESUs are sold as a subscription that runs for up to three years, and the Azure Arc route is described as a pay-as-you-go subscription model compared with the classic ESUs offered through the Volume Licensing Center, which are purchased in yearly increments. Annual billing through Volume Licensing is handled by a Microsoft representative.

So the ask to the account team is specific: the per-core annual rate for SQL Server 2016 under the April 2026 model, whether that rate is flat across the three years, and what the same estate would pay under pay-as-you-go through Azure Arc. Get both in writing, because the two billing shapes produce different cash profiles over a three-year ESU term even if the list rate is identical.

One cost is published. Connecting SQL Server instances to Azure Arc is free of charge, and the Arc agent is what makes the pay-as-you-go subscription available. The cost of that route is implementation time, not a licence line, which is why it is the cheapest thing to test before the July 2026 date.

Three routes a buyer actually shortlists

The first route is to subscribe to ESUs and stay where you are. On-premises, non-Azure cloud and hosted environments qualify after connecting the servers to Azure Arc, and if an instance cannot be connected to Azure Arc it does not qualify for that offer. The fallback for a disconnected estate is volume licensing, which Microsoft says to discuss with the account team, and disconnected instances can then be registered manually in the Azure portal.

The second route is to move the workload to Azure and keep running SQL Server on a virtual machine. SQL Server on Azure VM customers subscribe when they register with the SQL IaaS Agent extension, and ESUs are available in all regions that extension supports. This is a lift-and-shift, not a rewrite, and it does not bring free ESUs for SQL Server 2016.

The third route is to upgrade to a supported version or migrate to Azure SQL, which ends the ESU subscription automatically. Microsoft points at Azure SQL Managed Instance and Azure App Service as ways to avoid end of support and stay current, and at Azure Migrate for upgrading the OS version while migrating. That route trades a three-year subscription for a project with its own cost and its own slip risk.

A fourth option exists on paper and is worth naming because it is the one procurement asks about: buy ESUs through volume licensing without Arc. It requires Software Assurance under one of the agreements Microsoft lists, and it is billed in yearly increments rather than pay-as-you-go. For an estate already on an Enterprise Agreement, that is the least new plumbing.

How the shortlist compares on price model, term and what you get

The table below sets the three routes against the criteria the April 2026 pricing change moved: how you pay, how long the commitment runs, and what the subscription actually delivers. The delivery column matters because ESU licences do not include support for the underlying SQL Server version, and support is limited to issues deploying, installing and activating the updates, such as bugs or regressions introduced by a specific update.

Patch delivery follows the channel you already run. Instances with automatic updates enabled receive ESUs automatically, and instances with automatic updates disabled can download them from the Extended Security Updates pane in the Azure portal. Patches also arrive through Microsoft Update, Windows Update, System Center Configuration Manager or Azure Update Manager.

Region coverage is broad but not universal. In Azure you can subscribe in any region supported by SQL Server on Azure VMs, Azure VMware Solution or Nutanix, and outside Azure in any region that supports SQL Server enabled by Azure Arc. Check the supported region list before committing a datacentre to the Arc route.

One eligibility trap sits in the middle of this. SQL Server 2016 customers can subscribe when they register with the SQL IaaS Agent extension or connect to Azure Arc, but they are not eligible for free ESUs, and the same applies to Azure VMware Solution. The free-patch path is a SQL Server 2014 property, not a general one.

Where each route breaks

The Arc route breaks on connectivity. Microsoft is explicit that if you cannot connect your SQL Server instance to Azure Arc, you do not qualify for the offer, and the fallback is a volume licensing conversation. An air-gapped or tightly segmented estate therefore pays the volume licensing route or migrates, and the free agent does not help it.

The volume licensing route breaks on contract. It requires Software Assurance under one of the agreements Microsoft lists, and it is bought in yearly increments, so it commits budget in a shape that a pay-as-you-go subscription does not. It also runs through a Microsoft representative, which puts a sales cycle between the decision and the patches.

The migration route breaks on time. A SQL Server 2016 estate that has not started by now is working against a July 2026 end of extended support, and the ESU years that follow run to July 2029. Migration is a project with its own sequencing, and the ESU subscription is the thing that buys the quarters to run it, which is why the two are usually bought together rather than chosen between.

All three routes share one limit. ESUs cover critical-rated vulnerabilities only, with no regular cadence, so a team that needs predictable monthly patching for an audit is not served by any ESU option. That requirement points at the upgrade, not at the subscription.

The decision rule for a 64-core estate

Choose the Azure Arc pay-as-you-go subscription if the instance can be connected to Azure Arc and the workload has no migration date inside the next twelve months, because the agent is free, the subscription cancels when you migrate, and it avoids committing to yearly increments before the migration plan exists. Choose volume licensing through your Enterprise Agreement if the estate is disconnected from Azure Arc or Software Assurance is already in place and procurement prefers a single annual line, and accept that you are buying the same critical-only coverage at a term you cannot cancel mid-year.

Choose the upgrade or Azure SQL migration if the workload can move without a rewrite and the team can carry a project through 2026, because it ends the subscription automatically and restores full product support rather than the deploy-and-activate scope ESU licences carry. Wait on the migration only if the application owner cannot commit a date before July 2026, in which case buy one ESU year and use it to run the assessment rather than to defer the decision.

Before signing anything, ask the account team for the per-core annual rate under the April 2026 model, the same figure under Arc pay-as-you-go, and written confirmation of which of your instances qualify for free ESUs, since for SQL Server 2016 the answer is none of them.