Raising a lot for flood zones

Good day, 

I'm wondering if anyone has experience with buying lots in a floodzone? Let's say the zone is AE4. Does that literally mean I need to raise the lot 4ft to build? Or do I have to raise it to avoid flood insurance? If so how much can it cost to grade a lot up 4ft on a 1/4 acre? Or is it better just to add additional foundation height?

Thank you.