Some schools also consider a graduate degree from such schools, but usually they want to see that you have defended your thesis for this graduate degree. For example, you have had a Master degree in CS from U of Chicago, but you want to apply for MBA in Stanford. Stanford will look at your graduate transcript to decide if you have done thesis for your CS degree, if you have, they'll give you the waiver. Stanford is the only top school that I know will consider your graduate degree in US for TOEFL waiver purpose. Most schools only consider undergraduate degrees from US.