.NET LTS vs STS: Support Lengths, the 24-Month STS Change and Which Version to Use

The short answer

.NET LTS releases are supported for three years; STS releases are now supported for two. Microsoft ships a new major every November, even numbers are LTS and odd numbers are STS. Today .NET 10 is the LTS release to be on, supported until 14 November 2028. .NET 8 (LTS) and .NET 9 (STS) both reach end of support on 10 November 2026, because Microsoft extended STS from 18 to 24 months starting with .NET 9. Within either kind of release, you are supported only if you stay on the latest patch.

LTS vs STS: what Microsoft's policy says

Microsoft's .NET support policy gives each release type one rule:

• Long Term Support (LTS): "LTS releases are supported for three years after the initial release." Even-numbered releases are LTS.
• Standard Term Support (STS): "STS releases are supported for one year after a subsequent release. Releases happen every 12 months so the support period for STS is two years." Odd-numbered releases are STS. They used to be called Current releases.

Microsoft states that the difference is only the length of support. Both kinds get the same servicing: patches ship on Patch Tuesday, the second Tuesday of the month, though not every month has a .NET release, and a system must have the latest patch installed to remain supported. Each release spends most of its life in Active support, where it gets targeted functional fixes and security fixes, and its final six months in Maintenance, where it gets security fixes only.

The change: STS went from 18 to 24 months

On 16 September 2025 Microsoft announced that STS support would increase from 18 months to 24 months, starting with .NET 9, with no change to LTS. The reason was practical. Out-of-band packages that LTS applications depend on are sometimes built on the newer annual release, so an organisation that only runs LTS could end up with parts of its stack on an STS release that expired before its LTS base. Making STS end 12 months after its successor ships lines it up with the previous LTS. The visible result is that .NET 8 and .NET 9 end on the same day, 10 November 2026. .NET 7, under the old rule, got 18 months and ended on 14 May 2024.

.NET versions and support dates

The latest patches at the time of writing, from 8 September 2026, are 8.0.31, 9.0.20 and 10.0.12. .NET 11 RC1 is a go-live release, which Microsoft supports in production ahead of general availability; under the annual cadence, .NET 11 is due in November 2026.

LTS or STS: how to choose

• Choose LTS for line-of-business applications that are upgraded on a project basis, for regulated systems where each upgrade needs validation, and for anything you want to leave alone for a few years. Today that is .NET 10.
• Choose STS when you upgrade every year anyway, want new runtime and language features early, and have the test automation to move each November. Two years of support now gives a full year of overlap with the next release.
• Do not mix by accident. Check which runtime your out-of-band packages and container base images target, because that is exactly the drift Microsoft's 24-month change was meant to soften.

If you are on .NET 8 or 9 now, the deadline is the same for both: 10 November 2026. Moving to .NET 10 gives you support to November 2028. Our .NET 8 to 10 upgrade guide covers the breaking changes.

What happens at end of support

Microsoft stops shipping fixes and updates and no longer provides technical assistance for the version. Applications keep running, but new vulnerabilities in the runtime, ASP.NET Core or the base class library stay open. Microsoft's guidance is to uninstall versions you no longer use and not to run out-of-support software. For applications that cannot move by the date, the options are a fast upgrade, accepting the risk, or third-party patching while the upgrade is completed.

Where OSSeva fits

OSSeva for .NET ships CVE-patched .NET runtimes for .NET 6 and 7 and covers both LTS and STS releases past Microsoft's dates, including .NET 8 and .NET 9 after 10 November 2026, across the CLR, ASP.NET Core, Entity Framework Core and the base class library. OSSeva Assure adds NuGet dependency scanning and a migration assessment; OSSeva Operate adds 24/7 CLR and application monitoring, a 15-minute P1 response and execution of the version migration. .NET is priced per application runtime environment, not per CPU core or deployment. See .NET end-of-life dates, .NET 8 end of life, .NET 9 end of life, .NET 8 extended support and .NET 8 extended support providers, or book a discovery call for a quote.

Frequently asked questions

What is the difference between .NET LTS and STS?

Only the length of support. LTS releases, the even-numbered ones, are supported for three years. STS releases, the odd-numbered ones, are supported for two years, until one year after the next release ships. Both get the same patches while supported.

How long is .NET STS supported now?

24 months, starting with .NET 9. Microsoft extended STS from 18 months in September 2025. .NET 7 and earlier STS releases had 18 months.

Why do .NET 8 and .NET 9 end on the same day?

Because STS now ends 12 months after its successor ships. .NET 10 shipped in November 2025, so .NET 9 ends on 10 November 2026, the same day as .NET 8's three-year LTS window.

Is .NET 10 LTS?

Yes. .NET 10 was released on 11 November 2025 and is supported until 14 November 2028.

Is .NET 11 LTS or STS?

STS. It is odd-numbered, and under the current policy it gets two years of support. Its release candidate is a go-live build that Microsoft supports in production.

Should I upgrade from .NET 8 to .NET 9 or .NET 10?

To .NET 10. .NET 9 ends on the same day as .NET 8, so moving to 9 buys no time. .NET 10 is LTS and supported until 14 November 2028.