.NET 8 and .NET 9 both reach end of support on 10 November 2026. After that date Microsoft stops releasing security fixes for them. .NET 10, a Long Term Support release, is supported until 14 November 2028 and is the version to move to.
.NET end-of-support dates at a glance
| Version | Support type | End of support |
|---|---|---|
| .NET 8 | LTS | 10 November 2026 |
| .NET 9 | STS | 10 November 2026 |
| .NET 10 | LTS | 14 November 2028 |
Microsoft releases a new major version of .NET every November. Long Term Support (LTS) releases get three years of fixes; Standard Term Support (STS) releases get two, which is why .NET 9, released a year after .NET 8, ends on the same day.
What end of support means
Applications built on .NET 8 or .NET 9 keep running after 10 November 2026, but the runtime they depend on no longer receives security patches. That covers the .NET runtime, ASP.NET Core and the hosting bundle installed on Windows servers, and the base container images your applications are built from.
What to do now
- List every application, service and server that runs on .NET 8 or .NET 9, including in-house tools and the vendor software you host.
- For your own code, change the target framework to .NET 10, update packages, then build and test.
- Install the .NET 10 runtime or hosting bundle on servers before you deploy the upgraded applications. It can run side by side with .NET 8.
- Ask vendors when their products will support .NET 10, and record the answer.
- Once nothing depends on them, remove the .NET 8 and .NET 9 runtimes so old, unpatched versions don’t linger on servers.
Frequently asked questions
When does .NET 8 support end?
.NET 8 reaches end of support on 10 November 2026, after which Microsoft no longer releases security fixes for it.
When does .NET 9 support end?
.NET 9 also reaches end of support on 10 November 2026. As a Standard Term Support release it gets two years of support.
Which .NET version should I upgrade to?
.NET 10, a Long Term Support release supported until 14 November 2028.
Will my .NET 8 applications stop working?
No. They keep running, but the runtime underneath them no longer receives security updates, so newly found vulnerabilities stay unfixed.
Sources
Dates from Microsoft: .NET and .NET Core support policy. Always confirm dates with the vendor before making decisions.