It looks like Miscanthus sinensis var. condensatus 'Cosmopolitan'

Duh... at first I wondered why you needed an ID to create your screen - ah ha! you want to be able to buy more!
Donn, I wonder if it might just be Miscanthus sinensis 'Variegatus' - I'm not basing my guess on the leaf colouration. In my experience the var. condensatus cultivars aren't particularly vigorous in zone 5. The grass in the pic looks QUITE vigorous.

Whatever the cultivar ... fpozani, it looks like some of your grass is reverting back to solid green or there is a self-sown Miscanthus growing up in the centre. Either way, if left to its own devices, the solid green could eventually outgrow the variegated bits.

If you were to mark the solid leaves (string, twine ...?) before they turn tan in the fall. In the spring when you are cutting your grass back leave the 'marked leaves' uncut. Then, when you divide your grass you can either discard those bits or start up a whole new 'un-variegated' plant.

just at thought,
A.

Blade width is the reason I called it 'Cosmopolitan.' 'Variegatus' has much thinner blades.

Thanks for the replies. It's 'Cosmopolitan', which the nursery I bought it from sells. They don't have 'Variegatus'. I picked more up today.