Is it too late to plant grass seed in Maryland, USA? The ground is not frozen yet, temp today 28-43 f 11/23/08?

yes you can spread it, but it won't germinate till spring. Birds may eat it over the winter. Cover with seed free straw to hold it till spring.

peat moss is 'water phobic' and will repel water once it dries and is not a good top dressing.

The very best time to plant grass seed is just before a snowfall. The snow will help to push the seeds in the ground. Frozen ground will also help to get the seeds into the soil. They will germinate in the spring.

my experience has been that if you plant grass seed and mulch it with good organics life peat moss or whatever is used in your area it will lie dormant and when watered in the spring will germinate nicely.hope this helps

Doubt it will grow. If anything you might try a winter wheat or rye that is a cover crop. Very early spring would be best esp. if your area has suffered drought conditions.