Lumen LTS??

I know that Laravel 5.1 is an LTS branch and we have been using it for a few projects, one of which is a hybrid API. That API has some performance issues and we have decided to break it out of Laravel and put it in an API targeted framework. Lumen was just coming on the scene when we started this project and now that we have decided to change the framework I am curios if Lumen has an LTS branch? Lumen 5.1? Or is Lumen still too young?