I think what you have there is a severe case of snow mold. Thatch is a layer that lies on top of the soil, it doesn't mat down individual blades as it appears in your yard. Snow mold generally doesn't kill your grass unless it affects your crowns, but it will delay spring green up. This fall, after your grass has stopped growing, it would be beneficial to cut your grass lower than usual, 1.5-2 inches. Grass that's left too long going into winter can trap moisture as it lays down, and provide a nice environment for snow mold to develop. It looks like your grass was left on the long side before the snowfalls. I would rake the grass to break up the matted blades, then give it a good mow a little shorter than usual, maybe 2-2.5 inches. Even though it's still cool in New England, I would probably water a bit more than needed to get the grass growing. I would discourage seeding, as spring seedings generally don't do all that well, and you might be surprised how well grass can come back from snow mold. If you don't see any results in 1-2 weeks, then you might want to think about seeding, but again, late summer/early fall is the best time.

Follow tiemco's advice to a "T". May first apply 1/2# of N/k. If you can find it (go to a garden center or a Lesco), use a triple 10, 12 or 19 fertilizer and immediately water it in.

Agreed - your guess was not quite correct. Tiemco knows his stuff and has saved you considerable work. In June you will be laughing at the idea that you wanted to seed.

KBG is the type of grass that, once it gets established, never needs more seed...unless you want to add different varieties of KBG or you want to bring in some fescue.

Hopefully your soil test is from Logan Labs or UMASS. Those are the only two labs anyone trusts anymore. Don't bother fertilizing until you have mowed green grass for the second time. If you apply too soon your roots will not take it up and it's wasted. Besides, when the grass comes back from dormancy, it comes back with a vengeance anyway. You don't need to add fertilizer to rapidly growing grass. Fertilizing early will not make it come out sooner.

N.E. had more than its fair share of snow this winter. It is very likely that turf has been injured by snow mold. At the very least, its going to deplete its reserves trying to grow new blades. Roots are active at some level anytime the soil is not frozen. Applying a triple NPK fertilizer will insure the turf has the nutrients needed for regrowth and help spreading of the healthy KBG. If the OP had said it was fescue, I might agree with dchall that it hasn't come out of dormancy and to waite, but it's KBG.

Awesome, thanks guys. I will wait for the soil test to get back before doing anything different, but in the mean time I will rake it and mow a tad lower as recommended. Then I'll hit it with triple NPK.

As for watering, wait until above is done of start now? The nights are still pretty cool here.