Could be one of hundreds; without a bloom there's not much uniquely identifiable about it. It's actually looks to be in good shape to me health-wise.

This is a terrible year for plants. I think a lot of places out there this year are facing rain deficits, so there's going to be weak growth and skimpy blooms. I've lived in PA my whole life, and never have I seen it this dry and sunny. I go out to nurseries and see overwintered stock and one or two truckloads - after that, nothing. I think one hardware store gave up on plants and is liquidating what's left.

Congratulations on your new home. A home with hydrangeas is a happy one, providing the interior US isn't turning into a dust bowl!

Thanks! Yep I'm in Chicago and if this isn't a drought I don't know what is! I've done lots of new planting and am struggling to keep everything happy and healthy!

Do you think it is a Mac?

Most of Chicago is approx a Zone 5b and most macs do not well in Zone 5. The problem is that the plant survives but the blooms tend not survive so the macs that you can see out there would be reblooming macs.

Paniculatas, oakleafs and some arborescens will survive in your Z5. They should be all starting to bloom now though. However there are a few that do not start until very very late (July). If you get no blooms by the end of the next month, I would back to thinking that it is a mac.

Is it not possible to get the answer from the previous home owner? Some people grow macs in very cold zones like yours but they winter protect the macs so the blooms will not be lost. If they prev owners were busy selling the house, the mac may not have been winter protected so it now has no blooms.

(Yes, that's a mac)