My wife and I bought a new house last September so this spring I'm working on renovating the lawn. Attached are some pictures of a few random spots in my back yard that are pretty heavy in dead/brown grass. My question is, do I need to dethatch my lawn? Or do I need to aerate it? I've read in a few different places that dethatching isn't neccessary aerating will help with thatch. With that, I've read that people wait until fall to aerate and seed, but being the impatient person I am, I'd rather get the problem taken care of early so allow the yard to grow. With that said, I'm very new to lawn care so I'm not sure if that is a good way to think, and if that is the correct process. Can somebody help me and give me some suggestions on how to fix this problem? I've read that having a heavy thatch problem leads to fungus growth, and I noticed I had mushrooms growing in multiple places last fall. I'm also assuming/wondering if a lot of my grass is brown/dead because I'm not getting proper oxygen and water to my lawn from a thick layer of thatch? I've already applied Fertilizer with Dimension, which was about a month ago so I'm not sure I need to do that. I'd greatly appreciate any help!