Can this be added at the dealer? I wanted one but my truck has arrived without one.

 

I'm sure it can. The tailgate won't be cheap though.

 

It is an expensive thing to do after the fact there are some after market things you could do: https://www.bestop.com/trekstep/

 

Ford parts site: 2017 Ford F-250 Super Duty Tailgate Assembly w/Step | FordParts.com $783.20

 

I just went through this. No you can not just add the step. I had assumed that all you would need to would be to purchase the step assembly and new trim for the top of the tailgate. Turns out Ford makes 2 tailgates making it impossible to do just that like you could in the older generations. I ended up purchasing a used damaged tailgate that had the step and having my local Ford dealer body shop repair and paint to match my truck. That way it had a lifetime guarantee on the workmanship and paint. You will also need to replace the driver's side tailgate hinge to accommodate the new tailgate with the step. It's not cheap but considerably cheaper than buying a new one from Ford.

 

I searched around and could not find a Bestop for the 2017's. Had one on my 2016 and liked it.
I wound up buying an AMP Research BedStep for my 2017. More money than the Bestop for pretty much the same thing. I was told by another poster here that the AMP was all metal, hence the higher price than the Bestop. Not so for the model I bought. The step itself is plastic (resin, they call it). But everything else is aluminum alloy.
Lowest price I found was at tonneaucovered.com and I got the step in 2 days.

 

It seems like it would be handy, I have a step but I thought about adding one for when you don't need to or can't open the gate. Do you like it?

 

Just installed it yesterday. I liked it on my 2016, and with the 2017's being a little taller I'm sure I'll like it that much more this time around.
I was in & out of the bed a hundred times the other day when doing a spray in bed liner. For that I just used a 4' step ladder.
I've got longer running boards, so I don't need an additional step to access the bed from up near the cab. But with a tonneau cover that becomes moot anyway most of the time.

 

Honestly the tailgate step seems like a relatively useless option to me, I've never even used mine. Even with the 37's on my truck I just jump up there.

 

You're fortunate. I'm almost 55 and in pretty good shape from running up & down ladders all the time with my business. But the day is coming where I'm slowing down and any little assistance like the step just might save me a pulled muscle or from falling backward and a more serious injury while climbing into the back of the truck.
Ain't too proud to give myself a little assist with that now & then!

 

Hell, I'm so old I need a step stool to reach the factory tailgate step!

 

Fair enough, I likely won't always be able to do this myself.

 

Coming to us all someday!