AWS Developer Tools Blog
AWS SDK for .NET V3 Maintenance Mode Announcement
In alignment with our V4.0 GA announcement and SDKs and Tools Maintenance Policy, version 3 of the AWS SDK for .NET will enter maintenance mode on March 1, 2026, and reach end-of-support on June 1, 2026. Starting March 1, 2026 we will stop adding regular updates to V3 and will only provide security updates until end-of-support begins.
Support Timeline
When we announced the general availability of AWS SDK for .NET V4 on April 28, 2025, we committed to a support timeline tied to the AWS Tools for PowerShell, which depends on the SDK. With AWS Tools for PowerShell V5 reaching general availability in August 2025, the 6-month support window for V3 began. For more details on the original support commitment, see the V4.0 GA announcement.
The following table outlines the level of support for each phase of the SDK lifecycle.
| SDK Lifecycle Phase | Start Date | End Date | Support Level |
| General Availability | July 28, 2015 | February 28, 2026 | During this phase, the SDK is fully supported. AWS will provide regular SDK releases that include support for new services, API updates for existing services, as well as bug and security fixes. |
| Maintenance Mode | March 1, 2026 | May 31, 2026 | During the maintenance mode, AWS will limit SDK releases to address critical bug fixes and security issues only. AWS SDK for .NET v3.x will not receive API updates for new or existing services or be updated to support new regions. |
| End-of-Support | June 1, 2026 | N/A | AWS SDK for .NET v3.x will no longer receive updates or releases. Previously published releases will continue to be available via public package managers and the code will remain on GitHub. |
Next Steps
We encourage the AWS SDK for .NET community to begin planning your migration to V4 as soon as possible:
- Review the Migration Guide to understand the breaking changes.
- Test your applications with V4 in a development environment.
- Update your code to accommodate the changes.
- Provide feedback through our GitHub repository.
Conclusion
With the maintenance mode transition now in effect and end of support on June 1st, 2026, we recommend prioritizing your migration planning to ensure a smooth transition. Migration documentation is available to guide you through the update process.
For questions or issues that arise while updating to the V4 SDK, please use the GitHub repository’s discussion forums or open GitHub issues to reach out to us. If you find dependencies that are preventing you from updating to V4, please let us know to see if we can help.