From the flower structure, it looks to be a lacecap, therefore either a macrophylla or serrata. The vast majority of these bloom on old wood, so pruning should be kept to a minimum.

Here is a link that might be useful: how/when to prune hydrangeas

Another paniculata.

Thanks to you both, but I'm a little confused on this one.

One of you said it was an amacrophylla, but another said it was a paniculata. If I understand your information, the paniculat blooms on new growth and the other blooms on old growth.

Completely different way to trim and prune them, right?

Thanks for your help!

You are correct. But based on the form of the flowers - not panicles (i.e. a 'paniculata') but in a lacecap form with few sterile flowers still remaining as well as the way the flowers are arranged on the branches (not the growth pattern of a paniculata), I am standing by my initial conclusion that this is a macrophylla or closley related serrata.

The branching and smaller leaves indicates paniculata to me as well. It will be easier to ID it when it is in bloom next year rather than going on dead flowers and leaves today.

A closer shot showing a flower, leaves, branches/buds should make it pretty easy to tell apart a Mac from a paniculata. I am not familiar with serrata.

That would be a paniculata, which has flowers shaped like "cones". A macrophyllas is lower mounded plant and would probably never get that tall in your climate Zone. I'm in Illinois, for reference.