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Office 2021 Loses Security Support This Week
Office 2021 stops getting security patches on October 13, 2026. Here is what that means for law, medical and CPA offices, and what to check this week.
By Kevin Woolf2 min read
Microsoft is ending security support for Office 2021 on October 13, 2026, according to Microsoft's own lifecycle page (opens in a new tab). That is today. If your front desk, billing, or back office PCs are still running the perpetual, one-time-purchase version of Office 2021, instead of Microsoft 365, they stop getting security patches starting then.
This is not a feature update you can skip. It is the plug being pulled on patches for Word, Excel, and Outlook. Once a flaw is found after October 13, it stays open. Nobody fixes it, because Microsoft has moved on.
Why this matters for your office
Office is where the real work happens. Staff open attachments in it, draft letters in it, build spreadsheets with client numbers in it. In a law firm, that is privileged correspondence. In a medical or dental practice, that can touch protected health information. In a CPA office, it is tax returns and financial records.
An unsupported copy of Office sitting on a front-desk PC is the kind of hole that does not stay small. It is also exactly the kind of known, unpatched target that automated attacks are built to find. You do not want to be the office that still had Office 2021 running when something got in through it.
What to do this week
- Check your Office version. Open Word or Excel, click File, then Account, and look at the version listed. If it says Office 2021, Office 2019, or similar, and not Microsoft 365, that machine is affected.
- Walk the office and make a list. Front desk, reception, and back office computers are usually the ones nobody got around to upgrading. Write down every PC still on the old version.
- Decide on the move to Microsoft 365 now. Waiting does not make the risk smaller, it just adds more days without patches.
- Ask about Copilot while you are at it. If you are moving to Microsoft 365 anyway, it is worth seeing how Copilot can help with drafting and routine document work in your office.
I can make the move from Office 2021 to Microsoft 365 straightforward, keep your files and settings intact, and walk your staff through what changes. If you want a hand with this, or just want someone to confirm whether your machines are affected, that is a normal part of what I do for law, medical, and accounting offices in Polk County. More on how I handle security for offices like yours is on my cybersecurity page.
This is general information, not legal advice.
