Do I pay extra for 4K service?

You cannot simply enable 4K in your account. This requires a specific equipment install as there is only a single 4K Mini Genie Client and requires specific Genie or Genie-2 to support it.

There is no cost for 4K itself. Just need the 4K install.

HR54 Genie on non 4K tv (Can connect to a 4K tv, but will not provide the 4K feed to it).

C61K Mini Genie Client (wired only at this time) on 4K tv.

Remember Client has no tuner of its own, uses 1 from the Genie.

4K tv must support HDCP 2.2, HDMI 2.0, and 60FPS

DirecTV Installation, 4K tv must be there

Package Select or above as of 12/15/2016 (used to be only Ultimate or Premier). So only the Family package will not get 4K service at all.

 

At this time there are only a couple channels in 4K (plus a few PPVs)

Even if you have multiple C61K or RVU clients, only one tv can be using a 4K channel at a time.

Genie-2 (HS17, server tower) can be used instead of HR54. But this model has some restrictions that can make it a downgrade for many. So not suggested without full research that it is going to be right for you.