5 min read
Why Microsoft’s Move to 24-Month STS Support Is a Big Deal for .NET Teams
Microsoft is now supporting .NET STS releases for 24 months (instead of 18), aligning lifecycles and easing upgrade pressure for teams. Let’s break down what that means and how to adapt.
Key Takeaways
- Extended stability: STS releases now receive 24 months’ support vs 18, giving teams more breathing room.
- Flexibility in upgrades: You can adopt a more relaxed cadence without risking falling off support prematurely.
- Ecosystem alignment matters: Dependency management, library support, and internal policies must evolve to make the most of this shift.
When Microsoft announced that .NET STS (Standard Term Support) releases will be supported for 24 months, up from the prior 18-month window, many in the .NET community paused to reflect on the implications. In short: this is more than just a numbers tweak. For development teams, product owners, and operations, it’s a meaningful shift in how you can plan upgrades, manage dependencies, and reduce risk.
Here’s what’s changed, why it matters, and how to make the most of it.
What Changed — and Why
The Old Rhythm: 18 Months for STS
Historically, Microsoft designated even-numbered .NET releases (e.g. .NET 8) as Long Term Support (LTS), supported for three years. Odd releases (e.g. .NET 9) were STS and got support for 18 months (i.e. six months after the next release shipped). That shorter window often forced teams to pick stable LTS versions to avoid frequent rework, especially in regulated or enterprise environments.
The New Rhythm: 24 Months
Under the new policy, STS releases will be supported for 24 months, i.e. for 12 months after the successor release ships. That means .NET 9, under the new plan, will be supported until November 10, 2026 (same as .NET 8). LTS timelines remain unchanged (3 years) under this update.
Why Microsoft Did It
This change wasn’t for marketing — it addresses real pain:
- Dependency drift in out-of-band (OOB) packages: Some packages evolve faster than the major release train. A library may bump a dependency to a newer STS version, unintentionally forcing a different support timeline. The 24-month window reduces the risk of inadvertently “falling off support” midstream.
- Better planning stability: Teams can now align upgrade cadences more flexibly (not locked into upgrading STS versions every ~1.5 years).
- Lower friction for using STS: With more breathing room, STS versions become more viable for production, not just experimentation.
What It Means for Your .NET Strategy
Rethink STS vs. LTS Tradeoffs
Before, STS versions often felt like a temporary or risky bet unless you were committed to upgrade frequently. Now, with an extended support window, STS may be more palatable for longer-lived projects or those that want newer features without committing to the LTS “pendulum swing.”
Dependency & Package Strategy
Library maintainers now have to support a longer window for STS versions. That means for third-party or in-house libraries, your support burden may stretch further. However, the stability benefit may outweigh that extra effort.
Upgrade Cadence
You can now plan upgrades more deliberately: not every STS wave, but maybe every two releases, or when there’s a compelling feature or performance improvement. The extended window gives buffer for quality assurance, integration testing, and migration paths.
Risk Mitigation
Longer support reduces the risk of “falling off support” prematurely, especially when your application uses a mix of LTS, STS, and OOB packages. It helps ensure your runtime and dependencies stay on a stable path for a longer time.
How to Adapt (Actionable Steps)
- Review your current .NET versions & roadmap
- If you’re on an STS version nearing end-of-support under the old plan, reassess whether you can stretch a bit longer under the new window.
- Recalculate support timelines for all your services, libraries, and dependencies.
- Audit dependencies and OOB packages
- Identify packages that might “pull forward” a runtime dependency to a newer STS.
- Ensure your libraries are compatible across the extended support window.
- Adjust upgrade cadence & planning
- Given the extra buffer, you can move from “upgrade every STS version” to “upgrade every two or three releases,” if it aligns with your risk tolerance and feature needs.
- Build in more testing and staging phases — you now have more runway.
- Communicate with stakeholders
- Explain to leadership, product, and operations teams that longer STS support means lower pressure for constant updates.
- Reassess internal policies that may have been rigid around only using LTS versions.
- Track policy changes over time
- Microsoft’s support policies evolve; keep an eye on announcements around .NET lifecycles.
- Subscribe to official .NET lifecycle or roadmap feeds so you’re not caught by surprise.
Potential Challenges & Considerations
- Library maintenance overhead: Some open-source or internal libraries may find the extended STS window burdensome, as they’d need to maintain compatibility longer.
- Version churn: Even with 24 months, major feature changes or breaking API shifts across versions can still force migrations.
- Adoption inertia: Some organizations with strict rules may still prefer only LTS. Extending STS support may make it more acceptable, but it won’t override deeply held policies.
If you’d like help planning your .NET version roadmap under the new STS support regime, let’s talk!
Tim Yocum
At YTG, I spearhead the development of groundbreaking tooling solutions that enhance productivity and innovation. My passion for artificial intelligence and large language models (LLMs) drives our focus on automation, significantly boosting efficiency and transforming business processes.
