It looks like Safariland has some holsters for it, some having level 2 retention.
Use their holster finder here: http://holsterfinder.safariland.com/
Thread: Need Holster for FNX-40
Just purchased a new FNX-40 and cannot find a good holster for it with out major modifications to holsters.
I would prefer some level of retention
SHTF expect an order inbound!