Support of Qt 5.9 LTS ends in May 2020. If you are still with Qt 5.9 LTS, update to the soon released Qt 5.15 LTS or Qt 5.12 LTS is recommended. If you can't update, extended support is available for an additional fee after the standard support ends.
Long term supported releases of Qt are supported for three years, thus the support for Qt 5.9 LTS ends at the end of May 2020. Many users have already migrated to later releases, especially to Qt 5.12 LTS. Next week we have also Qt 5.15 LTS available, so those who have not yet switched to more recent versions of Qt are encouraged to do so now. Note that from Qt 5.15 onwards the long-term support is only available for commercial license holders.
Qt 5.9 LTS has been a great success story. It was the second LTS release of Qt 5 series, and received more patch releases than any other Qt release since Qt 2.3. During the lifetime of Qt 5.9 LTS total of 10 releases were created - all the way from Qt 5.9.0 in May 2017 to Qt 5.9.9 in December 2019. Qt 5.9 LTS is also a special release as a lot of work was put into the release process and related infrastructure specifically to be able to make a lot more patch releases than from any previous Qt 5 release.
But while Qt 5.9 LTS has been a great release, the more recent long-term supported Qt releases are even better. Therefore it is time to move on and take all the active projects forward to the currently supported releases of Qt. This allows you to continue enjoying improvements and bug fixes, support to new operating system and compiler versions, latest security updates - and of course a lot of new functionality available in the more recent releases.
If you can't switch to a supported version of Qt, Extended support is available. Especially if your Qt 5.9 LTS based application or device is actively maintained after May 2019, purchasing extended support is highly recommended. Extended support can be purchased both for Standard as well as Premium Support. To learn more about Extended support, please contact our Support team and watch Andy Shaw's excellent Qt Virtual Tech Con talk.