Microsoft confirmed on June 29, 2026 that .NET 8 and .NET 9 will both reach end of support on November 10, 2026. After that date, neither version will receive security updates, servicing fixes or technical support. Microsoft recommends moving to .NET 10, a long term support release supported through November 2028. With about a month left, businesses running .NET applications and the firms that maintain them should confirm their upgrade plans now.
What Microsoft announced
In a post on the .NET Blog, Microsoft explained why the two versions end on the same day:
- .NET 8 is a Long Term Support (LTS) release. It shipped on November 14, 2023 and receives 36 months of support.
- .NET 9 is a Standard Term Support (STS) release. It shipped on November 12, 2024. STS releases now receive 24 months of support instead of 18, which moves its end date to November 10, 2026.
| Version | Support type | Released | Support ends |
|---|---|---|---|
| .NET 8 | LTS, 36 months | November 14, 2023 | November 10, 2026 |
| .NET 9 | STS, 24 months | November 12, 2024 | November 10, 2026 |
| .NET 10 | LTS | Current LTS release | November 2028 |
Microsoft notes that applications will keep running after the deadline but will no longer be patched. Future Visual Studio 2022 servicing updates will mark .NET 8 and .NET 9 components as out of support, and the .NET Upgrade Assistant is listed among the migration resources.
InfoWorld's report on the announcement adds that the basic upgrade step is changing the TargetFramework property in project files to net10.0, and that the production release of .NET 11 is expected in November 2026.
Why it matters for companies hiring IT firms
Business applications, APIs and internal tools built in the last few years often target .NET 8, because it was the LTS release before .NET 10. Running them past November 10 means any newly found vulnerability in the runtime or in ASP.NET Core will stay open. For companies in regulated sectors, unsupported software can also become an audit finding.
The move from .NET 8 to .NET 10 is usually smaller than older framework migrations, but it still needs testing: third-party packages must support .NET 10, build pipelines and container images need updating, and hosting environments must have the new runtime installed. If you outsource this work, ask a .NET development company for an inventory of affected applications, a test plan and a realistic timeline that ends before November 10.
Useful questions to ask before you sign off on the work:
- Which of our applications, services and scheduled jobs target .NET 8 or .NET 9 today?
- Do all third-party libraries and components we rely on support .NET 10?
- Will hosting, containers and build agents need changes, and who makes them?
- How will the upgrade be tested, and what is the rollback plan if something fails?
Why it matters for IT firms
For firms that build and support .NET Core and ASP.NET applications, the deadline creates a short, concentrated wave of upgrade work. Clients on .NET 9 may not realize their version ends at the same time as .NET 8, because STS support used to be shorter and the change is easy to miss. Telling maintenance clients about the date early, and offering a fixed-scope upgrade assessment, is likely to be more useful than waiting for questions after support ends.
What to do next
- List every application, service and function that targets .NET 8 or .NET 9, including small internal tools.
- Check NuGet dependencies for .NET 10 compatibility and update CI/CD pipelines and container base images.
- Upgrade and test in a staging environment, then schedule production releases before November 10.
- If an application cannot be upgraded in time, document the risk and agree compensating controls with your security team.
Trusted IT Firms lists 122 companies offering .NET development. Compare providers in the company directory.
Frequently asked questions
When does .NET 8 support end?
.NET 8 reaches end of support on November 10, 2026, the same day as .NET 9.
Why does .NET 9 end on the same date as .NET 8?
Microsoft extended Standard Term Support releases from 18 to 24 months, so .NET 9, released in November 2024, now ends on November 10, 2026.
Will my .NET 8 application stop working after November 10?
No. Applications keep running, but Microsoft will no longer issue security updates or provide technical support for them.
Which version should I upgrade to?
Microsoft recommends .NET 10, a long term support release supported through November 2028.
Sources
Add trusteditfirms.com as a preferred source on Google, or open this page in your AI assistant to use it as a source.
