Even in its 2019 state, Office 2016 Pro Plus offers a robust toolset designed for professional productivity:
Thus, your string suggests the Office 2016 Pro Plus with the March 2019 cumulative update applied. MS Office 2016 Pro Plus 16.0.4738.1000 March 2019
Unlike Microsoft 365, which nags for online sign-ins every 30 days, this perpetual license works entirely offline after activation. For air-gapped or highly regulated environments (e.g., defense, manufacturing), this is irreplaceable. Even in its 2019 state, Office 2016 Pro
For the home user who bought a one-time license, for the IT director maintaining a stable legacy environment, or for the digital archivist preserving software history, this build is a reliable workhorse. It offers: For the home user who bought a one-time
No — mainstream support for Office 2016 ended , and extended support ended October 14, 2025 . Using 16.0.4738.1000 today means missing over 5 years of security updates. Microsoft recommends upgrading to Office LTSC 2021 or Microsoft 365 Apps for Enterprise.
Patching vulnerabilities in the Office "shared components" and graphics filters.