Experts and BHG readers answer.
Grass snow mold
In a very snowy year like much of us had this past winter, snow mold is very common. Hard to prevent it entirely. Good news is that it often only kills the grass blades, not the entire plant, so much of the damaged grass will grow back. Just break up that matted layer of dead grass with a rake to help it dry out.
To reduce snow mold next year, keep thatch under control, keep the lawn mowed a bit on the sort side going into winter, and don't apply a winterizer fertilzer (i.e don't fertilze any later than Sept). That's about all you can do without the use of fungicides, which are available and certainly effective. But given the relatively superficial damage caused by this disease, I wouldnt' recommend spending the money.