Fortinet labels this as "Mature" support.
The device is now in its "must-fix" or "End of Support" phase, meaning it generally only receives critical security patches for PSIRT vulnerabilities rather than new features. Upgrade Path & Process fortigate 200d latest firmware updated
End of Support Life (EOSL): It is currently in the period where it primarily receives critical security patches and bug fixes within the 6.0 branch. Why Updating is Non-Negotiable Fortinet labels this as "Mature" support
The absolute latest firmware version officially supported for the FortiGate 200D is . While some users have experimented with later versions on similar hardware, the 6.0 branch is the final stable destination for the 200D model. How to Update Your FortiGate 200D Firmware fortigate 200d latest firmware updated