I've had good results with this, don't forget the surfactant.

Here is a link that might be useful: Sedgehammer

Where do you live?
Are you sure it is nutgrass and not green kyllinga? Because nutgrass is a swamp grass and kyllinga is a desert grass. Check out the differences in the seed heads on Google Images. Different approaches are needed to discourage them. Of course you could use Sedgehammer and really discourage them to death, but for every day discouragement, you might want to change your watering schedule.

What kind of soil do you have? (sandy or clayey)

Did you rototill to prepare the lawn?

I live in pennsylvania with clay soil. Our house was built in 2009 and i layed tall fescue sod last year. Fairly confident it is nutsedge

Hit it with Sedgehammer and follow label instructions.

It usually is nutsedge. I went for a couple years with green kyllinga thinking it was nutsedge, too, so that's why I asked. My nutsedge never really gets started. It comes every few years and then goes away by itself. I believe it has to do with rainfall and the way my soil (under the surface) will hold water. There seems to be pockets where the sub soil is impenetrable a few inches down. Those spots hold water like a bucket. Nutgrass LOVES the swampy conditions, but when the soil dries out, the nutgrass goes away. Kyllinga, on the other hand, has not been watered ever and looks fresh as a daisy.