Microsoft 365 Apps End of Life (EOL) Dates & Support Timeline

Microsoft 365 Apps lifecycle status — the real story

Microsoft 365 Apps (the subscription Office desktop apps: Word, Excel, Outlook, PowerPoint and the rest) per version, generated by tools/microsoft-365-apps-lifecycle.mjs from Microsoft's own Update history for Microsoft 365 Apps on Learn (read 2026-09-10). Versions carry Microsoft's YYMM labels (2608 = August 2026). releaseDate = the first day the version shipped to the Current Channel, from the Version history by date table. eol = the latest End of service date Microsoft states for the version on any update channel in the Supported versions table; a version no longer on that table is out of service on every channel and is marked end-of-life without a published date, because Microsoft prints no historical end-of-service dates and nothing is derived.

Channel policy, in Microsoft's words on the update-channels overview: Current Channel versions are serviced until the next version ships (about a month); Monthly Enterprise Channel versions are serviced for three months (the second Tuesday of release to the second Tuesday three months later); Semi-Annual Enterprise Channel receives Monthly Enterprise Channel builds from July 2026, so the enterprise channels now share one end-of-service date per version. That is why only the three newest versions carry a dated end of service at any time.

Inventory note: asset tools report Microsoft 365 Apps by build (16.0.20326.20144). The build-to-version map is Microsoft's Supported versions table (20326 = 2608); the page here is keyed by version.

Microsoft 365 Apps release and support pattern

Across the 117 release lines with a published release date, Microsoft 365 Apps has shipped a new line roughly every 4 weeks (median interval). A line typically stays supported for about 4 months from its release to its end-of-life date (measured on the 3 lines with both dates published).

Of the 117 release lines tracked, 114 are past end of life and 3 are still within support; 114 are marked end of life without a published date. The newest line, 2608, was released August 19, 2026. The next scheduled end of life is 2606 on October 13, 2026 — 32 days from this build. The longest-supported line currently published is 2608, to December 8, 2026.

Computed from the tracked release data at every build — the figures above are the dates in the table, restated, not an editorial estimate.

What does Microsoft 365 Apps end of life mean for your organization?

When a version of Microsoft 365 Apps reaches end of life, the maintainers stop issuing security patches. Vulnerabilities discovered after this date are publicly disclosed on the National Vulnerability Database, exploit code appears on GitHub, and your systems remain permanently exposed.

The CVE blind spot: Most vulnerability scanners check for known CVEs but do not flag the accumulation of unpatched vulnerabilities in EOL software. With a zero-day, nobody knows about the vulnerability. With EOL software, the vulnerability is public — listed, rated, and often weaponized — but no patch will ever exist. This is the most dangerous gap in enterprise security posture.

Organizations running EOL Microsoft 365 Apps should treat it as a vulnerability class in their risk register, apply compensating controls (network segmentation, enhanced monitoring, access restriction), and prioritize migration to a supported version.

Your options when Microsoft 365 Apps reaches end of life

There are four realistic paths. Which one is right depends far more on how long the system needs to keep running than on the version you are on today.

How to choose, in one question: how many more years does this system need to run? Under a year, extended support (where it exists) is usually cheaper than an emergency migration. One to three years, migrate — support purchased repeatedly costs more than doing the project once, and the project only gets harder as the version ages. Indefinitely, migrate now and plan the next migration before it surprises you.

Worth saying plainly, because vendors selling extended support rarely will: extended support is often the more expensive choice over a multi-year horizon. It is the right answer when a deadline is genuinely unreachable, not as a default. Compare the annual fee against the one-time cost of migrating before committing to either.

Formalizing decisions like this across your estate? Our free EOL policy template is a ready-to-adopt policy with risk tiers, remediation SLAs, and audit mapping — no signup, free to use and share.

Extended Support Options

If you cannot migrate immediately, extended support vendors provide continued security patches for EOL Microsoft 365 Apps versions. This is a bridge, not a permanent solution — plan your migration in parallel.

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