Yes, any required forms will be included with the Efiled 1040X.

In my case, only change was adding form 8606, are you suggesting the 8606 will be attached to the

1040X?

Everybody is under the assumption that what is needed is being sent, but nobody here can say with certainty what is or isn't attached.  It would be nice if Intuit would provide a nice little list of what is being packaged up with an e-filed return.  Folks have been asking the "what's included" question for as long as Intuit has provided a forum.  In response to that question, Intuit has provided us with badges 😕

8606 can be filed by itself. You don't need to do a 1040X.

I know one of the mods addressed this over a month ago and said you don't need to attach anything to an Efiled amended return, everything would be included. 

My guess is that it sends the entire filing copy again but includes the 1040X, I cant see it picking and choosing what goes and what doesn't.

Can you direct me to that module reference please?  I did see in 8606 instructions

that a stand alone 8606 cant be filed if a 1040 was previously filed, an amended return

is needed, thanks in advance

Apparently I can't. The instructions say you can file by itself if you are not required to file a 1040. 

I was wrong. Or maybe I was right once but they changed the rules.

Ok I see, thanks, can I send a message to tech support to inquire? I dont use this feature 

too often, thanks 

@IntuitAustin  can you verify that all necessary pages of an amended return get included when you Efile the 1040X?