After Canadian customers of the Galaxy Note 4
on the Rogers network were said to start receiving a Marshmallow update, word has just broke out that US customers of the Galaxy S5 branded with the Verizon network are also being issued their share of the Marshmallow update. Early April, Sprint led the pack with its own Galaxy S5 variant packing the Marshmallow OS, while T-Mobile soon followed gifting it with the soon-to-be an older Android build.
The over the air update currently being released by Verizon will feature a MMB29M.G900VVRU2DPD1 build number.
Since the update is still in its early roll-out stages, it usually takes a number of days or sometimes weeks before all devices on the network receive it. If you want to accelerate the process, you could try checking manually by going into Settings >> About Device
and then tap Check for Updates