Microsoft will end support for Office LTSC 2021 on October 13, 2026. After that date, devices running LTSC 2021 will stop receiving security fixes, bug fixes, and technical support. Organizations must migrate to Microsoft 365 or upgrade to Office LTSC 2024 to remain supported.
Only six months remain until Office LTSC 2021 reaches end of support on October 13, 2026. Organizations must assess risk and plan upgrades to avoid security, compliance, and productivity gaps.
Main feature/change and impact
Microsoft will stop providing security fixes, bug fixes, and technical support for Office LTSC 2021 on October 13, 2026. This change removes vendor-supplied security patches and increases exposure to vulnerabilities and compliance failures. Devices remaining on LTSC 2021 will also miss feature improvements and cloud integrations that modern productivity and security tooling require.Practical implications
Enterprises should plan migrations to Microsoft 365 suites or Office LTSC 2024 for disconnected scenarios. Microsoft 365 E3, Office 365 E3, and Microsoft 365 Apps provide always-supported apps, centralized management, and enterprise-grade security. Organizations under 300 users can adopt Microsoft 365 Business plans for built-in services like Exchange Online and OneDrive. FastTrack and App Assure can aid migration for complex environments.Continuing to use software after end of support can leave your devices vulnerable to potential security threats, productivity losses, and compliance issues.Plan inventory, timelines, and testing now to avoid rushed upgrades near the deadline. For devices that cannot move to cloud, evaluate Office LTSC 2024 as the supported on-premises option. Use Microsoft Lifecycle and upgrade guidance to document compatibility and licensing changes. Prepare migration steps: inventory installations, classify dependent line-of-business apps, and pilot Microsoft 365 Apps or LTSC 2024 on representative hardware. Allocate time for testing macros, add-ins, and authentication flows. Engage FastTrack or third-party partners for migrations over 150 seats, and schedule phased rollouts to minimize business disruption.
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